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In dogs after feeding increased plasma insulin concentration is positively related in converting the "fasted" pattern of electrical activity into the "fed" pattern. In sheep, the release of insulin induced by a perfusion of volatile fatty acids is accompanied by similar changes in the pattern of electrical activity. The results indicate that insulin release induced by nutrients plays a major role in the control of intestinal motility in both species.

Relationships between the basic motor patterns of the small bowel, i.e. the occurrence at hourly intervals of myoelectric complexes and absorption of glucose were studied in vivo on 2-m length ovine jejunum isolated loops by means of the "perfusion marker" technique. For a mean flow rate of about 480 ml/h, the net glucose movement during queiscence was decrease at the occurrence of the phase of irregular spiking activity (ISA) and increased during the phase of regular spiking activity (RSA) of the myoelectric complex. When the flow rate was nearly halved (225 ml/h), the net absorption of glucose was decreased at the occurrence of the phases of either ISA or RSA of the complexes.

The effects of increased doses (0.05-02 mg/kg) of morphine and nalorphine on colonic motility were investigated in 15-22 h fasted dogs fitted with two strain gauge transducers on the transverse colon at 8 and 15 cm from the ileo-colonic junction. These effects were compared to those obtained after previous administration of naloxone (0.3 mg/kg), atropine (0.1 mg/kg) and methysergide (0.1 mg/kg). Both morphine and nalorphine, at a dose of 0.1 mg/kg increased the colonic motility index by 285 and 248% from 0 to 60 min respectively after their administration, these effects lasting 3.2 and 2.6 h. These stimulatory effects were abolished by previous administration of naloxone (0.3 mg/kg) or atropine (0.1 mg/kg) and limited to 60 min after methysergide (0.1 mg/kg). It was concluded that nalorphine may be considered as a potent morphinomimetic substance upon colonic motility and that cholinergic and serotonergic receptors were involved in the colonic response to morphine.

The monoamine and catabolite contents of a large number of rabbit (n = 95) and cat (n = 32) carotid bodies (CBs) have been measured by high performance liquid chromatography with electrochemical detection (HPLC-ED). The dopamine (DA) content as well as that of its precursors tyrosine (TYR), dihydroxyphenylalanine (DOPA) and catabolites dihydroxyphenylacetic acid (DOPAC), homovanilic acid (HVA) were approximately equal in both species. The noradrenaline (NA) content was 10 times larger in the cat than in the rabbit CBs. Twenty-nine out of the 32 cat CBs contained more NA than DA while the reverse was true in 92 out of 95 rabbit CBs. In 11 cats the right CB was sympathectomized and its DA and NA contents were compared to those of intact contralateral organs.