Insulin and growth hormone in lean and obese pigs.

Abstract

Plasma glucose, immunoreactive insulin (IRI), and growth hormone (GH) were determined in fasted lean and genetically obese pigs at 1, 3, and 6 mo of age. Rate of glucose clearance and plasma IRI and GH response in provocative stimulation were also measured. Fasting glucose was similar in lean and obese pigs, whereas glucose clearance rate was more rapid in lean pigs. Obese pigs were not hyperinsulinemic but had lower plasma GH than lean pigs. At 1 mo of age, both lean and obese pigs had higher plasma IRI and GH as compared to 3 and 6 mo. Glucose infusion produced increases in plasma IRI at 1, 3, and 6 mo, respectively, with the greatest increases at 6 mo. Plasma IRI peaked at the same level in both pig types at a given age; but due to a more prolonged response in obese pigs, the overall IRI response to glucose infusion was greater in obese pigs. Arginine infusion caused much smaller IRI responses than glucose, but the response of obese pigs was significantly greater than that of lean pigs. Both provocative stimuli caused increases in plasma GH. The GH response to glucose infusion in obese pigs was considerably less than in lean pigs. These observations suggest mild insulin insensitivity and a reduced GH secretory potential in the obese as compared to lean pigs.

Evaluation of metabolic, endrocrine and growth features in the Mexican hairless pig to determinate its potencial as model for obesity in comparison with commercial pigs

“…This result is due to differences in body composition, size and growth rate between the two types of pigs. The differences observed in our study are similar to those reported between Yorkshire pigs and Ossabaw pigs (Wangsness et al, 1977) an obese pig with a similar phenotype as the Mexican hairless pigs.…”

Expression of insulin-like growth factor-1 (IGF-1) and growth hormone-receptor (GHR) mRNA in liver, skeletal muscle and adipose tissue of different breeds of pig

“…Buonomo and Klindt (1993) demonstrated differences in plasma IGF-1 concentrations between selected obese and lean genotypes in the neonate, being higher in the lean genotype, but found that these differences were diminished after 14 weeks of age (98 days), which would also agree with this study, since the pigs would be at least 150 days old (and even older in the slower growing Meishan X Landrace). Other studies of plasma GH concentrations indicated a suppressed GH status in pigs selected for high backfat, compared with those selected for lean (Althen and Gerrits, 1976;Wangsness, Martin and Gahagan, 1977), along with decreased foetal serum GH in preobese pigs (Martin et al, 1985).…”

Administration of Recombinant Human Insulin-Like Growth Factor I to Pigs: Determination of Circulating Half-Lives and Chomatographic Profiles

“…Indwelling femoral artery catheters were surgically implanted in male castrate Yorkshire pigs (42 kg mean body weight) as described by Wangsness et al [11]: anesthesia was induced with sodium thiamylal and maintained with 2-4% halothanc in oxygen administered via tracheal intubation. Tygon microbore catheters that had been previously coated with heparin (TDMAC) were exteriorized to the back of the pig and closed with a two-way stopcock attached to a protective canvas patch glued to the animal's back.…”