Effects of cysteamine on pulsatile growth hormone release and plasma insulin concentrations in sheep.
Comp Biochem Physiol B Biochem Mol Biol
; 112(3): 523-33, 1995 Nov.
Article
en En
| MEDLINE
| ID: mdl-8529029
ABSTRACT
The effects of cysteamine (CSH; 0, 50, or 100 mg/kg BW), a somatostatin depleting agent, on growth hormone (GH) and insulin (INS) secretion were studied in sheep (Ovis aries). Cysteamine was administered as a single intragastric bolus on day 0 (0900). Jugular blood samples were collected at 15-min (GH) and 2-hr (INS) intervals over an 8-hr period (1100-1900) on day 0, 3, and 7. Intragastric administration of CSH at 50 mg/kg BW augmented (quadratic, P = .04) mean plasma GH concentration, with the greatest response occurring on day 3. Baseline GH concentrations were elevated in wethers dosed with 50 mg/kg BW CSH on day 3, whereas wethers dosed with 100 mg/kg BW CSH had lower baseline GH concentrations on day 0 (CSH x day interaction, P = .02). Cysteamine administration increased GH pulse amplitude (quadratic, P = .15), with the greatest magnigtude of change occurring with 50 mg/kg BW CSH on day 0 and 3. Frequency of GH pulses was increased (quadratic, P = .10) following CSH treatment. Administration of 100 mg/kg BW CSH augmented plasma INS on day 0 (CSH x day interaction, P = .09). These findings indicate that CSH alters GH and INS secretion in a dose-dependent and temporal manner. The observed changes in mean and baseline plasma GH concentrations associated with 50 mg/kg BW CSH are consistent with somatostatin depletion; however, higher doses of CSH appear to disrupt GH secretion by an alternative mechanism.
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Bases de datos:
MEDLINE
Asunto principal:
Ovinos
/
Hormona del Crecimiento
/
Cisteamina
/
Insulina
Límite:
Animals
Idioma:
En
Revista:
Comp Biochem Physiol B Biochem Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Año:
1995
Tipo del documento:
Article
País de afiliación:
Estados Unidos