Growth hormone, insulin, glucose, cortisol, luteinizing hormone, and diabetes in beagle bitches treated with medroxyprogesterone acetate

1987 ◽  
Vol 116 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Joseph P. McCann ◽  
Norman Altszuler ◽  
Jennifer Hampshire ◽  
Patrick W. Concannon
Keyword(s):  
Insulin Resistance ◽  
Growth Hormone ◽  
Luteinizing Hormone ◽  
Medroxyprogesterone Acetate ◽  
Serum Concentrations ◽  
Cortisol Levels ◽  
High Doses ◽  
And Control

Abstract. Adult beagle bitches (20 to 101 months old) received medroxyprogesterone acetate (MPA; 75 mg/kg, im) or control vehicle at 3 month intervals. Changes in serum concentrations of GH, insulin and glucose were determined in 18 MPA-treated and 6 of 12 control bitches at 0, 2, 4, 8, 16 and 17–24 months of treatment (Exp. I). GH, LH and cortisol responsiveness to combined im injection of TRH (10 μg/kg), GnRH (10 μg/kg), and ACTH (5 μg/kg) was determined in 9 MPA-treated and 9 control bitches at 17 months of treatment (Exp. II). In Exp. I, serum concentrations of GH at month 2 (2.6 ± 0.3 μg/l), 4 (3.0 ± 0.3 μg/l), 8 (4.0 ± 1.2 μg/l), 16 (8.5 ± 1.7 μg/l), and 17–24 (21.2 ± 4.1 μg/l) of treatment were greater (P < 0.05) than pretreatment (1.4 ± 0.07 μg/l) and control (1.5 ± 0.1 μg/l) levels. The increase in GH at 2 months preceded (N = 4) or coincided (N = 2) with the development of hyperinsulinaemia and insulin resistance in 6 of the 18 treated bitches, two of which became diabetic by 17 months of MPA treatment. GH (24.6 ± 5.0 vs 11.4 ± 2.1 μg/l) and insulin (308 ± 77 vs 119 ± 9 pmol/l) concentrations were greater (P < 0.05) in older (49 ± 4 months; N = 12) than in the younger (26 ± 2 months; N = 6) treated bitches at 17–24 months of MPA treatment. In Exp. II, pretreatment concentrations of GH were increased (9.8 ± 3.0 vs 1.4 ± 0.1 μg/l, P < 0.01), cortisol levels decreased (12 ± 5 vs 72 ± 10 nmol/l, P < 0.01) and LH concentrations (0.9 ± 0.2 μg/l) unaffected in MPA-treated bitches. After injection of tropic hormones, GH was unchanged, whereas the rises in LH and cortisol levels were less (P < 0.01) in MPA-treated bitches than in control bitches. The results demonstrate that high doses of MPA increase GH concentrations within 2 months and that the GH overproduction and its diabetogenic-like effects were more pronounced in the older than in the younger treated bitches.

SERUM FOLLICLE-STIMULATING HORMONE, LUTEINIZING HORMONE AND PROGESTERONE CONCENTRATIONS IN PSEUDOPREGNANT RATS TREATED WITH MEDROXYPROGESTERONE ACETATE

1976 ◽  
Vol 70 (3) ◽  
pp. 465-471 ◽  
Author(s):  
W. J. DE GREEF ◽  
J. DULLAART ◽  
G. H. ZEILMAKER
Keyword(s):  
Luteinizing Hormone ◽  
Medroxyprogesterone Acetate ◽  
Follicle Stimulating Hormone ◽  
Corpora Lutea ◽  
Progesterone Concentration ◽  
Vaginal Smears ◽  
The Mean ◽  
And Control ◽  
Stimulating Hormone

SUMMARY Pseudopregnant rats were treated early in pseudopregnancy with 1 or 10 mg medroxyprogesterone acetate (MPA). Serum FSH, LH and progesterone concentrations were determined on days 2–20 of pseudopregnancy in treated and control rats. The mean duration of pseudopregnancy was 13·5 days in the control animals, but when animals were treated with 1 mg MPA a dioestrous period of 21·4 days was observed. A period with leucocytic vaginal smears of at least 2 months was observed after treatment with 10 mg MPA. Injection with MPA on day 3 of pseudopregnancy did not affect the serum FSH concentrations during the subsequent days. The progesterone pattern was alike in the three groups of animals, i.e. the duration of the activity of the corpora lutea was similar in all groups. However, 10 mg MPA slightly lowered progesterone concentrations on days 4–8 of pseudopregnancy. In the saline-treated rats, LH concentrations decreased from days 2–5, and remained low until they increased after day 11 of pseudopregnancy. This increase was delayed until day 20 in the animals treated with 1 mg MPA, and was not observed in the animals treated with 10 mg MPA. It is argued that the increase of LH concentration at the end of pseudopregnancy is not instrumental in the decrease of peripheral progesterone concentration but rather that the decrease in the progesterone concentration leads to the increase in the LH concentration.

Timing of growth hormone injections and reproduction in gilts

1991 ◽  
Vol 71 (3) ◽  
pp. 717-723 ◽  
Author(s):  
J. Gilbertson ◽  
R. N. Kirkwood ◽  
P. A. Thacker
Keyword(s):  
Growth Hormone ◽  
Ovarian Function ◽  
Elevated Serum ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Ovulation Rate ◽  
Serum Concentrations ◽  
Lh Pulsatility ◽  
And Control

Sixty-eight Yorkshire × Landrace gilts were selected at 85 kg body weight (BW) and exposed to a mature boar for 20 min d−1 to detect puberty. At the onset of puberty, gilts were allocated to receive daily intramuscular injections of porcine growth hormone (pGH, 90 μg kg−1 BW) from either 14 to 17 d (GH17, n = 22) or from 14 to 22 d (GH22 n = 22) after puberty, inclusively. A third group of gilts served as controls (n = 24) and received vehicle buffer. A single blood sample was obtained from each gilt on days 14, 17 and 20. Also, four gilts from each pGH treatment and eight control gilts were sampled at 15-min intervals for 8 h on day 16. Gilts were slaughtered 30 d after puberty at which time their ovaries were recovered for the determination of ovulation rate. Injection of pGH resulted in elevated serum concentrations of triiodothyronine, insulin and glucose (P < 0.01). There was no significant (P > 0.1) treatment effect on mean serum concentrations of LH or FSH. However, pGH treatment tended (P = 0.1) to increase LH pulse frequency and to decrease (P = 0.01) LH pulse amplitude. The incidence of a second estrus was reduced (P < 0.01) in GH22 compared to control gilts, with GH17 being intermediate (72.7 vs. 90.9 vs. 100% for GH22, GH17 and control gilts, respectively). Ovulation rate was not affected by pGH treatment (15.1 vs. 14.3 vs 14 0 for GH22, GH17 and control gilts, respectively). The present data confirm an adverse effect of pGH on ovarian function and suggest that an altered LH pulsatility may be involved. Key words: Gilts, growth hormone, estrus, endocrinology

scholarly journals Central infusion of leptin into well-fed and undernourished ewe lambs: effects on feed intake and serum concentrations of growth hormone and luteinizing hormone

2001 ◽  
Vol 168 (2) ◽  
pp. 317-324 ◽  
Author(s):  
CD Morrison ◽  
JA Daniel ◽  
BJ Holmberg ◽  
J Djiane ◽  
N Raver ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Luteinizing Hormone ◽  
Feed Intake ◽  
Serum Concentrations ◽  
Functional Link ◽  
Serum Leptin ◽  
Ewe Lambs ◽  
Hypothalamic Function ◽  
Maintenance Requirements ◽  
Serum Gh

Leptin has been implicated in the regulation of feed intake, growth, and reproduction. The objective of this study was to determine if centrally administered leptin would affect feed intake and the secretion of growth hormone (GH) and luteinizing hormone (LH) in ewe lambs. Eighteen ewe lambs were ovariectomized and fitted with intracerebroventricular (i.c.v.) cannulae. Lambs were randomly assigned to receive either a maintenance diet (fed), or a diet that provided 38% of maintenance requirements (diet-restricted) for 14 weeks. Subsequently, recombinant ovine leptin or vehicle was continuously infused, via i.c.v. cannulae, in a linearly increasing dose for 8 days, reaching a maximum of 1.25 microg/kg per h. Feed intake was recorded on days -1 to 7. Blood was collected via jugular cannulae every 10 min for 4 h on days 0, 2, 4, 6 and 8 for the determination of serum leptin, insulin, LH and GH. Leptin suppressed feed intake in fed lambs on days 4 to 7 (P<0.001), but had no effect on feed intake in diet-restricted lambs (P>0.25). Fed lambs had greater serum concentrations of leptin than diet-restricted lambs (P=0.007). Also, although not different on day 0 (pretreatment), on day 8 serum leptin concentrations were greater in leptin-treated lambs than in saline-treated lambs (P=0.003). Insulin was lower in diet-restricted than in fed lambs (P=0.003), but was not affected by leptin treatment (P=0.82). LH pulse frequencies were lower in diet-restricted lambs than in fed lambs (P=0.038), but were not affected by leptin treatment (P=0.85). Mean serum GH was greater in diet-restricted than in fed lambs (P<0.01). In diet-restricted lambs treated with leptin or saline, mean GH did not differ on day 0, but increased in response to leptin treatment (P<0.006). Treatment of fed lambs with leptin did not affect serum GH (P>0.32). From this work, we propose that leptin represents an important functional link between adipose stores and hypothalamic function in ruminants. We demonstrate that leptin concentrations change in response to reduced nutritional status, and that leptin has the ability to regulate multiple physiological processes in lambs, including both feed intake and secretion of GH.

Influence of medroxyprogesterone acetate (Provera) on plasma growth hormone levels and on carbohydrate metabolism

1981 ◽  
Vol 98 (4) ◽  
pp. 603-608 ◽  
Author(s):  
J. E. Eigenmann ◽  
R. Y Eigenmann
Keyword(s):  
Insulin Resistance ◽  
Growth Hormone ◽  
Carbohydrate Metabolism ◽  
Medroxyprogesterone Acetate ◽  
Insulin Response ◽  
The Other ◽  
Combined Effects ◽  
Glucose Load ◽  
Plasma Growth Hormone ◽  
Glucose Assimilation

Abstract. The combined effects of oestradiol and medroxyprogesterone acetate on growth hormone (GH) levels and carbohydrate metabolism were studied in 6 ovariohysterectomized dogs, which previously had shown moderate increments in GH after medroxyprogesterone acetate (MPA) administration. Oestradiol (Oe2) implants were administered 5 months after the last MPA injection, when MPA and GH levels tended to decrease. Following Oe2 administration GH levels rose significantly. Single MPA injections (100 mg) given 20 days after Oe2-priming were followed by still further increased GH levels. These GH levels were several-fold higher than GH levels achieved by previous MPA administration alone. GH levels decreased in 3 dogs after 35 days and remained elevated in the other 3 dogs as long as 70 days after MPA administration with Oe2 priming. Glucose assimilation became impaired and insulin response to a glucose load increased in relation to elevated GH levels. Oe2-primed control dogs, which received no MPA, failed to develop elevated GH levels. These findings indicate (1) that Oe2 and MPA induce overproduction in ovariohysterectomized dogs synergistically (2) that GH levels of the magnitude evoked are associated with glucose intolerance and insulin resistance.

Insulin action on protein metabolism in acromegalic patients

2003 ◽  
Vol 284 (4) ◽  
pp. E823-E829 ◽  
Author(s):  
Alberto Battezzati ◽  
Stefano Benedini ◽  
Annalisa Fattorini ◽  
Marco Losa ◽  
Pietro Mortini ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Growth Hormone ◽  
Protein Metabolism ◽  
Insulin Action ◽  
Glucose Disposal ◽  
Healthy Controls ◽  
Acid Protein ◽  
Surgical Cure ◽  
And Control ◽  
Amino Acid Protein

Insulin resistance in acromegaly causes glucose intolerance and diabetes, but it is unknown whether it involves protein metabolism, since both insulin and growth hormone promote protein accretion. The effects of acromegaly and of its surgical cure on the insulin sensitivity of glucose and amino acid/protein metabolism were evaluated by infusing [6,6-2H2]glucose, [1-13C]leucine, and [2-15N]glutamine during a euglycemic insulin (1 mU · kg−1 · min−1) clamp in 12 acromegalic patients, six studied again 6 mo after successful adenomectomy, and eight healthy controls. Acromegalic patients, compared with postsurgical and control subjects, had higher postabsorptive glucose concentration (5.5 ± 0.3 vs. 4.9 ± 0.2 μmol/l, P < 0.05, and 5.1 ± 0.1 μmol/l) and flux (2.7 ± 0.1 vs. 2.0 ± 0.2 μmol · kg−1 · min−1, P < 0.01, and 2.2 ± 0.1 μmol · kg−1 · min−1, P < 0.05) and reduced insulin-stimulated glucose disposal (+15 ± 9 vs. +151 ± 18%, P < 0.01, and 219 ± 58%, P < 0.001 from basal). Postabsorptive leucine metabolism was similar among groups. In acromegalic and postsurgical subjects, insulin suppressed less than in controls the endogenous leucine flux (−9 ± 1 and −12 ± 2 vs. −18 ± 2%, P < 0.001 and P< 0.05), the nonoxidative leucine disposal (−4 ± 3 and −1 ± 3 vs. −18 ± 2%, P < 0.01 and P < 0.05), respectively, indexes of proteolysis and protein synthesis, and leucine oxidation (−17 ± 6% in postsurgical patients vs. −26 ± 6% in controls, P < 0.05). Within 6 mo, surgery reverses insulin resistance for glucose but not for protein metabolism. After adenomectomy, more leucine is oxidized during hyperinsulinemia.

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