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The coronavirus disease 2019 (COVID-19) pandemic has casted a huge impact on global public health and the economy. In this challenging situation, older people are vulnerable to the infection and the secondary effects of the pandemic and need special attention. To evaluate the impacts of COVID-19 on older people, it is important to balance the successful pandemic control and active management of secondary consequences. These considerations are particularly salient in the Asian context, with its diversity among countries in terms of sociocultural heritage, healthcare setup and availability of resources. Thus, the Asian Working Group for Sarcopenia summarized the considerations of Asian countries focusing on responses and difficulties in each country, impacts of health inequity related to the COVID-19 pandemic and proposed recommendations for older people, which are germane to the Asian context. More innovative services should be developed to address the increasing demands for new approaches to deliver healthcare in these difficult times and to establish resilient healthcare systems for older people. Geriatr Gerontol Int 2020; 9999: n/a-n/a., (© 2020 Japan Geriatrics Society.)

We examined age-related changes in the turnover rates of synaptic membrane components that might underlie the decrease in synaptic functions in senescence. Synaptic membrane constituents were labeled in vivo with deuterium and the disappearance of the deuterated molecules from synaptic membranes was measured by mass spectrometry. The turnover rates of phosphatidylcholine, phosphatidylethanolamine, cholesterol, and synaptophysin were all shown to slow down with aging. Dietary restriction, which is known to retard various aging processes, was found to decrease the turnover rates of membrane lipid species. Consequently, the fatty acid composition in phospholipids remained unchanged in the synaptic plasma membranes of food restricted mice. In contrast, the turnover rate of synaptophysin was accelerated under dietary restriction. This may mean that increased turnover enhances the removal of damaged proteins from membranes., (Copyright 2002 Wiley-Liss, Inc.)

By means of skin organ culture, some biological characteristics of hair follicle elongation were examined. When skin sections from 6-day-old C3H mice were cultured, spontaneous elongation of hair follicles was maintained. Without insulin, hair follicle elongation was poorly maintained irrespective of the presence of serum at 20%. Insulin could be replaced by IGF-I at 100 ng/ml. During in vitro elongation of hair follicles, bromodeoxyuridine was incorporated into germinal epithelial cells around dermal papillae. Skin sections from 4-week-old C3H mice did not show hair follicle elongation in complete medium. However, when 0.5 mM minoxidil was added to the medium, concentration dependent thickening and elongation of hair follicles was observed. In contrast, in vitro elongation of newborn pelage hair follicles was not enhanced by minoxidil. These results suggest that this system with the use of skin sections from 4-week-old C3H mice would be a potential in vitro model of human androgenic alopecia in which the anagen phase is suppressed but the suppression is partially released by minoxidil.

Age-related changes in the renal functions were examined in rats of the Wistar/Tw strain. In male rats, renal plasma flow (RPF) and glomerular filtration rate (GFR) began diminishing at 13 and 16 months of age, respectively. Filtration fraction increased markedly at 13 months of age. Urine: plasma osmolality ratio decreased gradually after 10 months of age. Fractional water excretion (FEH2O) at 13-16 months of age was significantly greater than those at younger ages. These results indicate that the renal function in male Wistar/Tw rats begins to attenuate at about 10 months of age and the dysfunction becomes conspicuous at 16 months. On the basis of these data, the effect of androgen on the kidney was examined by estimating the renal clearance rates in castrated male rats and ovariectomized female rats treated with testosterone propionate (TP). Water intake, GFR and RPF in 13-month-old castrated male rats were less than those in age-matched normal male rats. On the other hand, in 7-month-old ovariectomized female rats treated with TP for 6.5 months, RPF and GFR became greater than those in age-matched control female rats. These results suggest that long-term exposure to androgen accelerates the renal dysfunction with ageing, resulting in the earlier development of polydipsia and polyuria in male rats than in female rats.

Lipofuscin is the autofluorescent material, which accumulates with aging in the cells of various tissues. However, its autofluorescence characteristics are different among tissues. In the present study, the autofluorescence features of lipofuscin in the brain and adrenal were compared. In 18-21-month-old rats, the brain lipofuscin was granular and its autofluorescence was bright whitish-yellow to bright orange. On the contrary, the adrenal lipofuscin was not demarkated as granules, and its autofluorescence was subdued orange. The emission maximum of the bright whitish-yellow brain lipofuscin was 540 nm to 570 nm and that of the adrenal lipofuscin was 640 nm to 660 nm, when excited at 330 nm to 380 nm. When the spectra were drawn after correcting the wavelength-dependent bias of microspectrofluorometer, the autofluorescence spectra were consistent with microscopically observable tint. To conclude, the present results showed that the autofluorescence features of the bright whitish-yellow brain lipofuscin and the adrenal lipofuscin were quite different.

The patterns of serum FSH, LH, PRL and GH levels in SHN mice were determined by radioimmunoassay between 1 and 12 months of age. In addition, the incidence of spontaneous development of uterine adenomyosis and mammary tumor was also studied for 12 months. Serum FSH level increased gradually with age while the level of LH was almost constant during the observation period. On the other hand, concentrations of PRL and GH significantly increased with age. The present data showed that the development of adenomyosis and mammary tumor rapidly increased after 6 and 9 months of age, respectively. Pituitary grafting at 30 days of age resulted in a high incidence of adenomyosis after 6 months of age. There were no significant differences in FSH and LH levels between mice with and without pituitary grafting. However, pituitary grafting resulted in the increase in PRL and GH levels compared with age-matched controls. These findings altogether suggest that the spontaneous development of adenomyosis in SHN mice may be related to the elevation in PRL and GH levels as a function of age.

Growth hormone (GH) secretion declines with age, while prolactin (PRL) secretion increases in rats. The age-related changes in the pituitary GH and PRL mRNA levels in the Wistar Tw rat were studied at 6, 12 and 18 months of age by cytoplasmic dot hybridization. Hormone and mRNA concentrations were expressed as values per micrograms GH-cell or PRL-cell DNA. Concurrent decrease in GH concentrations and GH mRNA concentrations with age was observed in female rats, but not in male rats. GH mRNA concentrations (per microgram GH-cell DNA) in male rats at 12 and 18 months of age were 88 and 66% of those at 6 months of age, but there was no difference. GH mRNA concentrations in female rats at 12 and 18 months of age were 51 and 53% of those at 6 months of age. A concurrent decrease in PRL concentrations and PRL mRNA concentrations was observed in both male and female rats. PRL mRNA concentrations (per microgram PRL-cell DNA) in male rats at 12 and 18 months of age were 37 and 18% of those at 6 months of age. PRL mRNA concentrations in female rats at 12 and 18 months of age were 51 and 31% of those at 6 months of age. Pituitaries in 12- and 18-month-old females contained more PRL and PRL mRNA than those at 6 months of age. These increases in PRL and PRL mRNA contents may result from the increase in the number of PRL cells, although each PRL cell had less PRL and PRL mRNA. These results suggest that the age-related changes in pituitary GH and PRL levels occurred at the transcription level of GH and PRL syntheses, and that the age-related changes in GH-cell and PRL-cell populations are responsible for the changes in GH and PRL secretions.

Age-related changes in hypothalamic luteinizing hormone-releasing hormone (LHRH) and luteinizing hormone (LH) secretion were studied in young (6 months), middle-aged (12 months) and old (18 months) female rats. The LHRH levels in the mid-hypothalamic area were higher in intact middle-aged and old females than in young ones. Additionally, there was no age difference in the hypothalamic LHRH levels in male rats. In order to clarify the significance of this age-related increase in female rats, we examined the effects of progesterone treatment in estrogen-primed ovariectomized young and old rats on the LHRH levels in the median eminence (ME) and on plasma LH levels. We found phasic changes in ME-LHRH and plasma LH levels in estrogen-primed rats following progesterone treatment in rats of both ages, but the progesterone-induced change in ME-LHRH levels tended to be delayed in old rats compared with young females. This delay may correspond to the delayed onset, slow and low magnitude of plasma LH increase in old females. The ME-LHRH levels were generally higher in old rats than in young rats. Nevertheless, we found that the increase in plasma LH in response to progesterone treatment in estrogen-primed ovariectomized females was smaller in old rats than young rats. These results suggest that the LHRH secretory mechanism changes with age in female rats. Such alterations may result in the accumulation of LHRH in the mid-hypothalamic area and an increase in ME-LHRH.

Luteinizing hormone-releasing hormone (LHRH) neurons were immunohistochemically studied in rats of both sexes at peripubertal ages. The number of immunoreactive LHRH neurons (irLHRH neurons) was counted in the brain region from the level of the septum-preoptic area to the level of the rostral part of the infundibulum in colchicine-treated male and female rats at 30 and 60 days of age. At 30 days, irLHRH neurons were more numerous in male rats than females. At 60 days, the number of irLHRH neurons in female rats increased to the level of male rats of the same age. In non-colchicine-treated rats, the count of irLHRH neuron was quite low. The difference in the number of irLHRH neurons between colchicine-treated and non-treated rats may be regarded as the activity of LHRH system. The difference in the number of irLHRH neurons was larger in male rats than in female rats at 30 days of age. On the contrary, at 60 days of age, the difference was larger in females than in males. LHRH contents were measured in the preoptic-anterior hypothalamic area (POA-AH), where LHRH neuronal perikarya are mainly located, and in the mid-hypothalamic area. LHRH content of the POA-AH in male rats at 60 days of age was not significantly different from that at 30 days of age. While, LHRH content in the POA-AH was greater in 60-day-old female rats at proestrous morning than that in 30-day-old females. At 30 days of age, male rats tended to contain more LHRH in the POA-AH than female rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Age-related changes in the regeneration of vasopressin (AVP) and oxytocin (OXT) axons after hypophysectomy in rats was immunohistochemically examined. Rats were hypophysectomized at 9, 16, 23, 30 and 90 days of age, and sacrificed 10 days after the operation. AVP or OXT immunoreactivity in the external layer of the median eminence (ME) was generally stronger in hypophysectomized immature rats than in hypophysectomized adult rats, and the age-related difference in immunoreactivity was more conspicuous for AVP axons than OXT ones. The cell body size of AVP or OXT neurons in hypophysectomized adult rats was not significantly different from the value of unoperated or initial control rats. However, the neurons in immature rats became significantly larger after hypophysectomy, compared with those of initial controls. These results indicate that AVP- and OXT-producing neurons in immature rats, as early as at 9 days of age, are endowed with the capacity of axonal rearrangement to the external layer of the ME after hypophysectomy, and that the stronger immunoreactivity in the external layer of the ME in immature rats than in the adult may be due to the differences in the rate of synthesis of neurohypophyseal hormones and the regenerative potency of neurons.

In the control theories, aging is under genetic and environmental control. Endocrine function plays an important role in this control system by mediating between the environmental influence and the presumptive "aging gene". Therefore, the intrinsic aging of the hypothalamus, such as the changes in sensitivity to feedback suppression or stimulation, may lead to homostatic failure and then age-related pathology. As the subject of study we have selected the senile changes in the hypothalamic-pituitary-ovarian axis in the rat of the Wistar strain. The cessation of estrous cycle and the onset of persistent estrus or repetitive pseudopregnancy usually take place as early as at the end of the first half of life in rats. In this paper the results of the following experiments are briefly dealt with: (i) reciprocal transplantation of ovaries between young and old rats (the term "old" designates here "incapable of reproduction"), (ii) comparison of LH and FSH binding abilities in the ovarian preparations, (iii) comparison of serum and pituitary concentrations of LH, FSH and prolactin and the modifications after ovariectomy or by the administration of pharmacological drugs, and (iv) the difference between young and old rats in intensity of dopamine fluorescence in the hypothalamus. The results of these experiments seem to point to the hypothalamic-pituitary part rather than more peripheral organs (ovaries) as being primarily responsible for the outcome of the senile changes in the female rat.

Changes of magnocellular neurons after hypophysectomy were immunohistochemically studied using antisera to arginine vasopressin (AVP) and oxytocin (OXT) in young and old female mice of the C57BL/Tw strain. AVP-immunoreactive neurons in the supraoptic and paraventricular nuclei of intact 19-month-old mice showed a marked reduction in number and immunoreactivity as compared with those of intact 3-month-old mice. Age difference of OXT-immunoreactive neurons was less pronounced than that of AVP-immunoreactive neurons. After hypophysectomy, both AVP- and OXT-immunoreactive neurons showed an intense stainability 10 days after the operation regardless of ages. However, the rate of reduction in number of immunoreactive neurons after hypophysectomy was less marked in 19-month-old than 3-month-old mice.

The changes of water intake, urinary volume, ratio of the water intake to the urinary output (water turnover rate) and urinary concentrations of sodium, potassium and chloride ions were investigated in male rats of the inbred Wistar/Tw strain during aging. Marked increase of the water intake, the urinary output and the water turnover rate as well as marked decrease of the urinary electrolyte concentrations were observed at the age of over 16 months. First signs of increase in the water intake and the water turnover rate were observed at the age of 12-13 months, but the initial reduction of urinary electrolyte concentrations was detected as early as at 7-9 months of age.

Neural lobe function in male rats of the Wistar/Tw strain was studied at 3, 7 and 16-18 months of age. A significant rise in the serum arginine vasopressin (AVP) level was noted in 16-18-month-old rats showing polydipsia and polyuria. The content and concentration of AVP in the neural lobe of aged rats were significantly less than those of younger animals (3 and 7 months). These results point out an enhancement of AVP release from the neural lobe of aged rats. The reduction in urinary volume in aged rats subjected to 24 hours of water deprivation was less than those in younger animals. No increase in urinary sodium, potassium and chloride concentrations was observed in aged rats, and the decrease in electrolyte excretion from urine during the dehydration period was less in aged rats than younger ones. These results suggest that the antidiuretic response to osmotic stimuli was reduced in aged rats. The administration of AVP to aged rats resulted in a significant decrease in water intake and urinary volume, but AVP administration did not induce any change in the electrolyte balance. Therefore, it is concluded that the main cause of the development of polydipsia and polyuria is the decline in renal function but not in neurosecretory activity, although exogenous AVP can effectively reduce water intake and urinary output in aged rats.

1. The distribution of an endogenous inhibitor of calcium-activated neutral protease (CANP) and age-related changes in its activity were studied in male and female rats of different ages by a fluorometric assay on tissue extracts after heat treatment. 2. Ubiquitous distribution of CANP inhibitor in brain, cardiac muscle, lung, spleen, liver, skeletal muscle, kidney and testis and its abundance in spleen, liver and kidney was demonstrated. 3. Comparison in terms of units/ml of crude extracts showed that the level of CANP inhibitor exceeded that of CANP in most tissues and that the relative content of CANP inhibitor to mCANP and microCANP differed greatly among tissues. 4. Sex and species differences in CANP inhibitor activity in each tissue were of little significance. 5. Changes in CANP inhibitor during aging from 6 to 12 months was not obvious but senescent rats showed a tendency toward increased inhibitor activity. This increase was especially evident in the testis.

The anterior pituitary of colchicine-pretreated male and female rats from 20 days to 12 months of age was stained immunohistochemically with anti-rat prolactin serum. Immunoreactive mitotic cells were identified in all groups of rats. In adult female rats the mitotic index of prolactin cells was higher at oestrus than at other stages of the oestrus cycle and than that in male rats of comparable ages. If adult female rats were ovariectomized on the second day of dioestrus or on the day of proestrus, the mitotic indices at presumptive oestrus were less than those in sham-operated controls at oestrus. Estrogen administration to ovariectomized rats significantly elevated the mitotic index of prolactin cells at 48 h after the treatment. The mitotic indices of prolactin cells in female rats reached a peak at 60 days of age, and then decreased with age. In male rats the mitotic indices showed a steady decrease from the value at 20 days of age. A sex difference in the mitotic indices of prolactin cells was noted from 60 days to 12 months of age. The present results clearly demonstrate that differentiated prolactin cells can undergo mitosis and that a sex difference in the mitotic activity of prolactin cells is present during adult life.