C. Schneider

Cholecystokinin octapeptide decreases intake of solid food in man

Cholecystokinin octapeptide (CCK-OP) was reported to decrease the intake of liquid food in lean and in obese man. This study investigated the effect of CCK-OP on the consumption of real life food, i.e., of standardized sandwiches. Sixteen young non-obese females and males participated, after an overnight fast, each in two experiments. After a basal 30 min, saline or CCK-OP, 1.5 or 3.0 Ivy Dog Units/kg body weight/15 min, was infused in random double blind fashion, while sandwiches were placed in front of the subjects. For the next three 15-min periods, the subjects were instructed to eat as much as they liked. In the first 15 min after 3.0 as well as 1.5 U CCK-OP/kg/15 min significantly fewer sandwiches (50 and 17 percent) were eaten than after saline (p less than 0.01 and p less than 0.05) and less hunger was reported (p less than 0.02 and p less than 0.05). Self-reported activation decreased only with 3.0 U CCK-OP (p less than 0.005). Reports of well-bring , electroencephalogram, heart rate, and respiration were not altered. The results support the notion that CCK is involved in the regulation of food intake.

Naloxone does not alter the perception of pain induced by electrical and thermal stimulation of the skin in healthy humans.

&NA; It has been hypothesized that, in the absence of acute or chronic pain, a tonically active system exists involving opioid peptides, which ensures a certain level of pain insensitivity. Although various studies have failed to support this concept, it has been reported that in conditions of both experimentally induced and clinical pain, high doses of the opioid antagonist naloxone induced a state of hyperalgesia and thus seemed to set off this hypothetical system. Lower doses were, however, without effect or even acted as analgesics. This study investigated the effect of 5 and 20 mg naloxone i.v., compared to placebo, on the perception of pain in healthy humans. Pain was induced by two methods, using electrical and thermal stimulation of the skin, which have previously been shown to be sensitive to the effects of opioid as well as of non‐steroidal anti‐inflammatory analgesics. Each of 12 males and 12 females participated in 3 experimental sessions, in which the treatments were administered double‐blind according to a Latin square design. Threshold and tolerance to electrically induced pain and threshold to thermally induced pain were measured at 30 min intervals for 90 min before and 90 min after drug administration. Electrical stimuli were square wave constant current impulses of linearly increasing intensity; thermal stimuli were of constant intensity and variable duration. Threshold and tolerance to electrically induced pain were not altered by either dose of naloxone, whereas the threshold to thermally induced pain was significantly higher after both 5 and 20 mg naloxone than after placebo, the effects of the two naloxone doses not differing from each other. Subjects who were relatively pain sensitive did not react differently to the pain stimuli after naloxone administration than did subjects who were relatively pain insensitive. These results, which are consistent with those of previous studies, cast further doubt on the validity of the concept that there is, in the absence of pain, a tonically active system involving endogenous opioids, which ensures a level of pain insensitivity.

Effects of cisapride on jejunal motor activity in fasting healthy humans

The effects of cisapride on jejunal interdigestive motor activity were studied in 12 healthy men participating in three experiments each. Five minutes after an activity front (phase III) they received, in random double-blind fashion, 10 mg of cisapride, 4 mg of cisapride, or saline placebo by intravenous injection. Motor activity was recorded for 4 h. A pneumohydraulic perfusion system and five catheters with orifices positioned 10-30 cm beyond the ligament of Treitz were used. Cisapride increased phase II-type activity (p less than 0.001) and reduced the number of activity fronts dose-dependently. Compared with phase II after placebo, the activity prevailing after cisapride was characterized by a significantly higher number and amplitude of contractions as well as by a significantly greater area under the pressure curve. Moreover, a significantly higher proportion of contractions was propagated aborally. Self-rated abdominal grumbling increased dose-dependently. Except for mild sedative effects, no side effects occurred. We conclude that cisapride induces a prolonged and highly propagative phase II-like jejunal motor activity in fasting humans.

Effects of oral cisapride on interdigestive jejunal motor activity, psychomotor function, and side-effect profile in healthy man

Intravenous cisapride was shown to induce a phase-2-like pattern of human interdigestive jejunal motor activity containing an increased number of propagated contractions. This study investigated the effects of oral cisapride in 12 fasting healthy males. Jejunal pressures were recorded by a pneumohydraulic system and five catheter orifices positioned 10–30 cm aborad the ligament of Treitz. Single oral doses of 5 and 10mg cisapride, administered 5 min after an activity front under random double-blind conditions, induced a phase-2-like jejunal motor pattern with a significantly higher number and amplitude of contractions and significantly more aborally propagated waves than placebo (P<0.001), while the number of subjects with activity fronts decreased with increasing dose. Five and 10mg cisapride administered tid for three days affected psychomotor function, subjective feelings, and side-effect frequency, apart from increases in systolic blood pressure and heart rate, no more than placebo. It is concluded that in fasting man, oral cisapride induces a highly propagative phase-2-like jejunal motor pattern causing only minor side effects.

Ceruletide increases threshold and tolerance to experimentally induced pain in healthy man.

UNLABELLED Previous studies suggested that ceruletide might be endowed with analgesic and sedative properties. To investigate the effects of ceruletide on experimentally induced pain and on central nervous functions, two studies, each involving 24 healthy subjects, were carried out in random double-blind fashion. Every subject participated in three experiments one week apart. In study 1, 120 and 60 ng/kg/hr ceruletide IV increased threshold and tolerance to electrically and threshold to thermally induced cutaneous pain significantly more than saline (p less than 0.001), the higher dose being slightly more active. Only mild sedative effects occurred. Study 2 compared the effects of 60 and 6 ng/kg/hr ceruletide IV to those of 0.4 mg/kg/hr pentazocine IV and investigated whether these effects were naloxone reversible. Both ceruletide doses, 60 ng/kg/hr slightly more than 6 ng/kg/hr, elevated threshold and tolerance to electrically induced and threshold to thermally induced pain markedly, pentazocine acted stronger and longer than ceruletide (p less than 0.001). Naloxone reversed the effects of pentazocine but not of ceruletide. CONCLUSION ceruletide (1) exerts potent naloxone resistant analgesic effects, which, however, are inferior to those of pentazocine, and (2) produces only mild sedation.

Effects of a combination of oral naproxen sodium and codeine on experimentally induced pain

SummaryThe effect of an orally administered combination of naproxen sodium 550 mg and codeine phosphate 60 mg on threshold and tolerance to electrically induced pain, and on the threshold to thermally induced pain, was compared with the effects of naproxen sodium 550 mg alone, codeine phosphate 60 mg alone, and placebo. 16 female and 16 male, healthy young subjects, took part in four experiments on consecutive days of one week. On each day one treatment was administered, in random order, under double blind conditions. The combination increased threshold and tolerance to electrically induced pain and the threshold to thermally induced pain markedly more than did naproxen sodium alone. Naproxen sodium plus codeine was also more effective in increasing threshold and tolerance to electrically induced pain than was codeine alone; the latter increased the threshold and tolerance to electrically induced pain and the threshold to thermally induced pain markedly more than placebo. Naproxen sodium alone had a relatively weak effect on the three pain measures. Reaction time to acoustic stimuli and the side effect profile were not significantly influenced by any of the treatments, and no severe adverse effects occurred. It is concluded that the combination of naproxen sodium 550 mg and codeine phosphate 60 mg, as indicated by its effects on experimentally induced pain, can produce more intense analgesia than the same doses of naproxen sodium and codeine administered alone, and that naproxen sodium and codeine phosphate given in combination enhanced each others effect in an additive manner.

Ceruletide decreases food intake in non-obese man

Cholecystokinin decreases food intake in animals and in man. This study investigated whether the structurally related ceruletide reduces food intake in healthy non-obese man. Twelve females and 12 males participated, after an over-night fast, in each of two experiments. During the basal 40 min, saline was infused IV. Thereafter, the infusion was, in random double blind fashion, either continued with saline or switched to 60 or 120 ng/kg b. wt/hr ceruletide. Butter was melted in a pan and scrambled eggs with ham were prepared in front of the subjects, who were instructed to eat, together with bread and mallow tea, as much as they wanted. With 120 ng/kg/hr ceruletide, the subjects ate significantly less (16.8 percent) than with saline (3725 kJ +/- 489 SEM and 4340 kJ +/- 536, respectively; p less than 0.025). They also reported less hunger (p less than 0.005) and activation (p less than 0.005) and activation (p less than 0.01), and had longer reaction times (p less than 0.01) and a weaker psychomotor performance (p less than 0.025). 60 ng/kg/hr ceruletide decreased food intake only slightly (6.6%; 3089 kJ +/- 253 and 3292 kJ +/- 300 respectively) and no significant changes in the above measures occurred. In conclusion, ceruletide reduces food intake in man, thus resembling the effects of cholecystokinin.

Effects of the prodrug loperamide oxide, loperamide, and placebo on jejunal motor activity

This crossover, double-blind study investigated the effects of single oral doses of the prodrug loperamide oxide, which is reduced gradually to loperamide in the intestine, and loperamide on jejunal motor activity in 12 fasting healthy men. Five minutes after a phase III of the migrating motor complex (MMC), 2 mg loperamide oxide, 4 mg loperamide oxide, 4 mg loperamide, or placebo were administered. Thereafter, motor activity 10–30 cm aborad the ligament of Treitz was recorded with five catheter orifices at 3-cm intervals over 4 hr. Number of contractions and area under curve increased significantly with 4 mg loperamide and 4 mg loperamide oxide, the increases with loperamide oxide occurring more gradually. Placebo and 2 mg loperamide oxide had no discernible effects. With both 4 mg loperamide and 4 mg loperamide oxide, phase I of the MMC was slightly prolonged and phase II and the time from drug administration to the onset of the first phase III slightly shortened. The percentage of aborally propagated contractions in phase II increased with all active treatments, whereas the occurrence of phases III was not altered.

Impaired Gastric Emptying and Altered Intragastric Meal Distribution in Diabetes Mellitus Related to Autonomic Neuropathy

Previous studies in diabetic patients suggested a relationship between delayed gastric emptying and increased ingesta retention in either proximal or distal stomach, but the determinants underlying these abnormalities remained obscure. We aimed at assessing the impact of cardiovascular autonomic neuropathy, blood glucose concentration, long-term glycemic control, and other factors in 34 type I and 43 type II diabetic patients (ages 21–67 and 34–81 years, respectively). Emptying was slower (P < 0.04) in type I diabetic patients than in 20 healthy control subjects (ages 23–63 years). Patients with autonomic neuropathy (N = 45) had slower gastric emptying (P < 0.02) and retained more in the distal stomach (P < 0.0001) than patients without neuropathy (N = 32). Multiple regression analyses revealed that slow emptying and increased distal retention were significantly associated with autonomic neuropathy (P < 0.043, P < 0.0002), whereas blood glucose, glycemic control, diabetes duration, age, and other factors had no discernible influence. Thus, both slow emptying and increased distal ingesta retention seem primarily referable to autonomic neuropathy.

Effects of cisapride on postcibal jejunal motor activity

In the jejunum of fasting humans, cisapride induces a phase 2-like, highly propagative motor pattern. This study investigated cisaprides effects on the fed pattern of the jejunum. Starting 5 min after a phase 3 of the migrating motor complex, 18 healthy men received 5 or 10 mg cisapride or placebo orally in random double-blind fashion and ingested meals containing 1000 and 4200 kJ, respectively. Jejunal pressures were recorded pneumohydraulically with five catheter orifices 10–30 cm aborad the ligament of Treitz. After the 4200-kJ meal, total number and number of propagated contractions as well as area under the curve increased significantly more than after 1000 kJ. Following the 1000-kJ but not the 4200-kJ meal, 10 mg cisapride increased total number of contractions, number of propagated contractions, mean amplitude, and area under curve significantly more than placebo. Fed-pattern duration increased with the meals caloric content but was not influenced systematically by cisapride. In conclusion, cisapride stimulates jejunal motor activity and induces a propagative pattern after a 1000-kJ but not after a 4200-kJ meal, suggesting that it can produce no further stimulation when motor activity is near maximally enhanced already.