Reduction of body fat stores by inhibition of prolactin secretion

Summary Reductions of prolactin secretion by bromocriptine treatment for 24 days reduced fat stores (abdominal and epididymal fat depots) in hamsters by 25–49% compared with control animals. However, body weights and food consumption were not affected. These results further substantiate an important role for prolactin in regulation of fat metabolism and indicate that bromocriptine might be used to decrease fat stores.     

Timed bromocriptine administration reduces body fat stores in obese subjects and hyperglycemia in type II diabetics

Obese postmenopausal female volunteers were given timed daily oral dosages of bromocriptine, and tested for reduction of body fat stores. This dopamine agonist has been shown to reset circadian rhythms that are altered in obese animals and to reduce body fat levels in several animal models. The participants were instructed not to alter their existing exercise and eating behavior during treatment. Skinfold measurements were taken on 33 subjects as indices of body fat. The measurements (e.g., suprailiac) were reduced after six weeks by about 25%, which represents a reduction of 11.7% of the total body fat. These dramatic decreases in body fat, which are equivalent to that produced by severe caloric restriction, were accompanied by more modest reductions of body weight (2.5%), indicating a possible conservation of protein that is usually lost as a consequence of such caloric restriction. The effects of bromocriptine treatment on body fat and hyperglycemia were also examined in non-insulin dependent diabetics being treated with oral hypoglycemics (7 subjects) or insulin (7 subjects). Total body fat was reduced by 10.7% and 5.1% in diabetics on oral hypoglycemics and insulin, respectively, without any significant reductions in body weight.Hyperglycemia was reduced in most of the 15 diabetic subjects treated leading to euglycemia and even cessation of hypoglycemic drugs in 3 of the 7 subjects during 4–8 weeks of bromocriptine treatment. These findings support the hypothesis that obesity and type II diabetes may be treated effectively with bromocriptine when administered at the proper times and dosages.This is a process patented by Louisiana State University and licensed to Ergo, Inc., Newport, Rhode island. A. H. Meier and A. H. Cincotta have financial interest in the process.     

Timed bromocriptine administration reduces body fat stores in obese subjects and hyperglycemia in type II diabetics.

Obese postmenopausal female volunteers were given timed daily oral dosages of bromocriptine, and tested for reduction of body fat stores. This dopamine agonist has been shown to reset circadian rhythms that are altered in obese animals and to reduce body fat levels in several animal models. The participants were instructed not to alter their existing exercise and eating behavior during treatment. Skinfold measurements were taken on 33 subjects as indices of body fat. The measurements (e.g., suprailiac) were reduced after six weeks by about 25%, which represents a reduction of 11.7% of the total body fat. These dramatic decreases in body fat, which are equivalent to that produced by severe caloric restriction, were accompanied by more modest reductions of body weight (2.5%), indicating a possible conservation of protein that is usually lost as a consequence of such caloric restriction. The effects of bromocriptine treatment on body fat and hyperglycemia were also examined in non-insulin dependent diabetics being treated with oral hypoglycemics (7 subjects) or insulin (7 subjects). Total body fat was reduced by 10.7% and 5.1% in diabetics on oral hypoglycemics and insulin, respectively, without any significant reductions in body weight. Hyperglycemia was reduced in most of the 15 diabetic subjects treated leading to euglycemia and even cessation of hypoglycemic drugs in 3 of the 7 subjects during 4-8 weeks of bromocriptine treatment. These findings support the hypothesis that obesity and type II diabetes may be treated effectively with bromocriptine when administered at the proper times and dosages.     

Antagonism of catecholamine inhibition of insulin secretion by methysergide

Zusammenfassung Isoliertes Maus-, Hamster- und Kaninchenpankreas wurde in einer physiologischen Pufferlösung mit 3,0 mg/ml Glukose inkubiert. Dopamin ruft eine erhebliche Verringerung der radioimmunologisch reagierenden Insulinsekretion hervor. Die durch Dopamin ausgelöste Hemmung lässt sich teilweise oder vollständig durch den Serotoninantagonisten 1-Methyl-d-lysergsäure butanolamid (Deseril) aufheben.

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Supported by grants from the National Institute of Arthritis and Metabolic Diseases of the National Institutes of Health No. AM 01324, No. 5 T1 AM 5074 and No. K3 AM 17,954 and a Clinical Investigatorship from the Veterans Administration (JMF).     

In vitro stimulation of chicken pituitary growth hormone and prolactin secretion by chicken hypothalamic extract

Summary The effect of an acid extract of chicken hypothalami on the in vitro secretion of prolactin and growth hormone (GH) by dispersed chicken pituitary cells has been investigated. Both prolactin and GH release were stimulated in a dose related manner in the presence of the hypothalamic extract (HE). Somatostatin had no effect on the basal or HE stimulated release of prolactin although it did inhibit the HE induced release of GH.     

Reversible inhibition by CCl4 of bile secretion during isolated liver perfusion

Zusammenfassung Durch kurzzeitige Applikation von gasförmigem Tetrachlorkohlenstoff während Leberperfusion tritt eine rasche und reversibel verlaufende Gallesekretionshemmung ein. Diese Hemmung könnte auf Veränderungen von Transport- oder Permeabilitätseigenschaften der Leberzellmembran durch CCl₄ zurückgeführt werden.     

In vitro stimulation of chicken pituitary growth hormone and prolactin secretion by chicken hypothalamic extract.

The effect of an acid extract of chicken hypothalami on the in vitro secretion of prolactin and growth hormone (GH) by dispersed chicken pituitary cells has been investigated. Both prolactin and GH release were stimulated in a dose related manner in the presence of the hypothalamic extract (HE). Somatostatin had no effect on the basal or HE stimulated release of prolactin although it did inhibit the HE induced release of GH.     

Inhibitory effect of beta-ecdysone on protein synthesis by blowfly fat body in vitro

Synthesis of blow fly calliphorin and other blood proteins by larval fat body in organ culture is inhibited by beta-ecdysone. The findings suggest a novel function for the hormone.     

Vitellogenin synthesis induced in locust fat body by juvenile hormone analog in vitro

Summary Fat bodies from adult females ofLocusta migratoria continue to synthesize vitellogenin and other proteins when cultured in vitro. A strong secondary induction of vitellogenin synthesis was obtained in fat bodies cultured in the presence of methoprene, and a weaker but significant primary induction was also obtained using higher doses (>100 g) of methoprene.This work was carried out in Dr G.R. Wyatts Laboratory and I thank him for helpful discussions. I also thank Dr G. Staal (Zoecon Corp.) for supplying the methoprene and Pfizer Inc. for rimocidin sulfate. This research was supported by grants from the US NIH (HD 02176) and Canada NSERC.     

Inhibition of the preovulatory secretion of gonadotropins by prolactin in rats seems to depend on the strain used

Intraperitoneal injection of Rat Prolactin to cyclic female Rats results in preovulatory changes which depend on the strain of animals. Specifically, preovulatory surges of luteinizing hormone and follicle stimulating hormone were suppressed in Sprague-Dawley Rats while delayed but enhanced preovulatory surges of both gonadotropins were observed in Wistar strain.     

Gastric secretion during anaesthesia and its inhibition by metiamide and other drugs.

The histamine H2-receptor antagonist, metiamide, inhibits the acid gastric secretion produced by chloralose-urethane anaesthesia in dogs carrying gastric cannulae chronically. This secretion is also prevented by atropine and hexamethonium. "Spontaneous" gastric secretion of vagal origin in conscious dogs is also blocked by metiamide.     

Prolactin secretion inhibition by a new 8a-amino-ergoline,CH 29-717

Summary In rats, CH 29-717 inhibits basal and physiologically or chemically stimulated prolactin secretion. It is more potent than the standard bromocriptine.