Cysteamine-induced depletion of somatostatin in sheep: time course of depletion and changes in plasma metabolites, insulin, and growth hormone.

Abstract

Eight crossbred wethers (51 +/- 2 kg BW), surgically fitted with abomasal cannulas, were used to determine the extent and time course of cysteamine (CSH)-induced depletion of somatostatin (SRIF) in abomasal tissue and associated changes in plasma metabolites, insulin, and growth hormone (GH). Cysteamine was administered as a single i.v. bolus (50 mg.kg BW-1 x 10 min-1) on d 0. Abomasal biopsies were obtained on d -7, -3, 0, 1, 3, and 10. On d 0, additional biopsies were taken at 2, 4, and 8 h after CSH administration. Jugular blood samples were collected over 8 h at 15-min intervals on d -2, 0, and 1. Cysteamine administration decreased (P < .05) tissue SRIF on d 0 (2, 4, and 8 h), 1, and 3; maximal depletion (42 to 55% of Pre-treatment; Pre-trt) occurred during the initial 24 h, returning to Pre-trt by d 10. Gel chromatography of pooled -7 d abomasal tissue extracts showed five peaks of SRIF immunoreactivity; the predominate peak eluted in the same position as synthetic SRIF-14. Plasma glucose, lactate, and NEFA concentrations increased (P = .001) after CSH administration and reached peak at 2 h after treatment and declined to Pre-trt concentrations by 24 h. Insulin increased (P = .001) to a maximum at h 4 and returned to Pre-trt by 24 h. Mean and baseline GH were higher (P < .07) on day of CSH administration, and pulse amplitude was lower (P < .10) on d 0 and 1. These data show that CSH rapidly reduces SRIF in abomasal tissue in a reversible manner; suggesting that CSH-treated sheep may provide a SRIF-deficient model for studying the physiological role of SRIF in ruminants.

Effects of dietary supplementation of cysteamine on growth performance, carcass quality, serum hormones and gastric ulcer in finishing pigs

“…In rats and sheep the effect of Cs supplementation on physiological growth hormone secretion was dose-dependent and reversible. 5,12,13 However, significant changes in plasma growth hormone level were not observed in this study. In this study, dietary supplementation of Cs at 30 mg kg −1 significantly reduced the plasma glucagon level but increased the plasma T 3 level (Table 3).…”

Cysteamine hydrochloride increases bodyweight and wool fibre length, improves feed conversion ratio and reduces methane yield in sheep

“…It has been shown to produce rapid depletion of somatostatin (SRIF) concentrations and SRIF-like immunoreactivity in plasma, the gastrointestinal tract (GIT), and hypothalamus (Szabo and Reichlin 1981;Bakhit et al 1983;Yanling et al 1999) and capable of crossing the blood-brain barrier (Bousquet et al 2010). SRIF exerts inhibitory actions on growth, development, metabolism, nutrient absorption and digesta rate of flow through the GIT in ruminants (Faichney and Barry 1984;Barry et al 1985;McLeod et al 1995).…”

Metabolomic studies on the biochemical profile of urine from rats with acute cysteamine supplementation

“…CS is the simplest stable aminothiol found in the body and has only one known function: it is a precursor for the formation of hypotaurine, which is subsequently oxidized to taurine. Plasma lactate and glucose concentrations increase after acute CS administration, which peak at 2 h after treatment and decline to pretreatment concentrations by 24 h (McLeod et al 1995). In addition, acute CS increases the net portal-drained viscera release of b-hydroxybutyrate in sheeps (McLeod et al 1997).…”