The night monkey, a tropical monkey, is the only nocturnal simian; its thermoregulation was studied for comparison with other nocturnal or diurnal primates and other tropical mammals. Resting metabolic rate was 2.6 W (closed-circuit method) and 2.8 W (open-circuit method), 24 and 18% below the value predicted from body mass. The thermoneutral zone was very narrow; the lower critical temperature (LCT) was 28 degrees C and the upper critical temperature (UCT) was 30 degrees C. The body temperature (Tb) was at its minimum (38 degrees C) at an ambient temperature (Ta) of 25 degrees C, thus below the LCT. At low Ta, the increase in metabolic rate (MR) was smaller than predicted by the Scholander model, since MR intersected to a Ta 13 degrees C above Tb when extrapolated to MR = 0; this was attributed to a decrease of body surface area by behavior. The thermal conductance at the LCT was low: 2.3 W . m-2 . degrees C-1. Above the UCT, panting was the major avenue of heat loss. The response pattern of nocturnal habits, low resting metabolic rate, low thermal conductance, and panting in the night monkey, unique among simians, is found in many other mammals of tropical and hot desert habitats; it may be considered as an alternative adaptation to the thermal environment.

SUMMARY Manometric studies of the sigmoid colon were performed on 17 healthy volunteers and on 49 constipated patients, after a long period of fasting (18-20 hours). Motility was recorded using perfused catheters at basal level during 45 minutes, then 30 minutes after a 0 5 mg intravenous injection of neostigmine, and, finally, 30 minutes during and after a meal. Motor activity was assessed by a motility index (per cent of activity x mean amplitude of waves). In both normal and constipated patients, the basal motility index was very low (respectively 82 +16 and 110 + 113). This low level of activity was due to the long fasting period imposed on all the subjects. After neostigmine the motility index increased in both controls (347±256) and constipated patients (311±323); this test, however was found to be unreliable. The meal increased the motility index to significantly higher values than after neostigmine in controls (538±215). In constipated patients the mean meal motility index was comparable with that of controls (577 ±549) with a large distribution of individual values. Using the mean meal motility index ±2 SD of the control group as a term of comparison, the patients were segregated into three groups: 'hypomotor' patients (eight cases), 'normomotor' patients (33 cases), and 'hypermotor' patients (eight cases). From the evidence of this series of clinically well-defined constipated patients, it was concluded that only the meal test is able to segregate three significant patterns of sigmoid activity and that a large number (68%) of constipated patients exhibit normal sigmoid motor activity.Abnormal motor activity of the sigmoid colon has been described in various disorders, including the irritable colon syndrome, diverticulosis of the colon, diarrhoeal states, and constipation (Connel, 1962;Wangel and Deller, 1965;Kirwan and Smith, 1977). It has been shown that, in constipation, the colonic motor disorder consists mainly in over-segmentation: regardless of the underlying disorder, an over-active sigmoid colon inhibits the transit of stools (Chowdury et al., 1976). However, in previous studies of colonic motility (Meunier et al., 1978), it was observed that such over-segmentation was not always present in chronic constipation. The present study is an attempt further to investigate sigmoid motor abnormalities in chronic constipation. On the other "Address for correspondence and reprints requests: Dr P. Meunier,

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A seasonal variation in the urinary catecholamines output has been demonstrated in two simians kept under constant ambient conditions : the nocturnal Aotus and the diurnal Saïmiri sciureus. In Aotus, catecholamines output (NA + A), in spring, is higher than in other Primates including man and even more so in winter. Cold exposure increases the NA + A excretion in Aotus as it does in squirrel monkey and rat but the A output is particularly prominent in Saïmiri. Fasting does not alter significantly the catecholamines excretion. Associated fasting and cold exposure do not modify the adrenosympathetic response observed in Aotus in cold conditions alone, but depresses the sympathetic activity and greatly enhance the adrenomedullary excretion in squirrel monkey, as it is the case in rat. Associated fasting and cold represents a highly stressful situation for squirrel monkey but not for night monkey. Catecholamines metabolites (MN, NMN, DOPAC, HVA, VMA and MHPG) are found in urine of both species, DOPAC and VMA being predominant in Aotus but DOPAC and MHPG in Saïmiri. The proportions of conjugated forms vary according to the metabolite : DOPAC and VMA are mainly under free form but NMN, MN and MHPG are mostly conjugated in both species. The daily output of pooled adrenergic metabolites (expressed as ng/mg creatinine) is higher in Aotus than in Saïmiri and man. Both monkey species display a high adrenosympathetic activity which does not correlate with their resting metabolic rate.