title: Impaired secretion of growth hormone in experimental uremia: relevance of caloric deficiency.
abstract: To evaluate the impact of uremia and associated caloric restriction on physiologically pulsatile growth hormone (GH) release, we used deconvolution analysis of spontaneous plasma GH profiles in 5/6-nephrectomized male rats (NX, N = 9). Three different normal renal function sham-operated groups were used: rats fed a normal diet ad libitum (SAL, N = 9); NX pair-fed rats (SPF, N = 6); NX rats pair-fed for protein ingestion but calorically supplemented up to the energy intake of SAL (SPF+, N = 8). Severe renal failure was confirmed by much higher (P < 0.001) BUN in NX than sham groups. NX rats were growth retarded as shown by reduced (P < 0.01) weight and length gains as compared with sham animals. Deconvolution analysis (mean +/- SEM) of plasma samples obtained every 10 minutes over 6 hours, and 14 to 16 days after second stage nephrectomy showed that NX rats had a longer GH t(1/2) (17.0 +/- 1.8 vs. 11.6 +/- 0.8 min), less GH mass secreted per burst (48 +/- 15 vs. 95 +/- 16 ng/ml/pulse), lower secretory pulse amplitude (1.9 +/- 0.5 vs. 5.8 +/- 0.9 ng/ml/min), and a reduced total GH secretion (240 +/- 69 vs. 400 +/- 56 ng/ml/6 hr) than SAL rats. Corresponding data were not significantly different between NX and SPF, or between SAL and SPF+ groups. In summary, stunted rats with chronic renal failure exhibit a prolonged GH t(1/2) and suppression of GH secretory pattern burst mass. Control data from rats with normal renal function suggest that the amplitude-specific depression of GH secretion may be attributed, at least in part, to chronic renal failure-associated calorie deficiency.
authors.affiliation: Department of Pediatrics, School of Medicine, Hospital Central de Asturias, University of Oviedo, Spain.
authors.forename: E
authors.initials: E
authors.lastname: García
authors.forename: F
authors.initials: F
authors.lastname: Santos
authors.forename: J
authors.initials: J
authors.lastname: Rodríguez
authors.forename: V
authors.initials: V
authors.lastname: Martínez
authors.forename: C
authors.initials: C
authors.lastname: Rey
authors.forename: J
authors.initials: J
authors.lastname: Veldhuis
authors.forename: R J
authors.initials: RJ
authors.lastname: Krieg
mesh_terms: D000818:Animals; D002149:Energy Intake; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D006207:Half-Life; D007676:Kidney Failure, Chronic / Q000150:complications; D008297:Male; D009392:Nephrectomy / Q000379:methods; D009748:Nutrition Disorders / Q000150:complications; D051381:Rats; D017207:Rats, Sprague-Dawley; D014511:Uremia / Q000150:complications / Q000378:metabolism*
chemical_list: D013006:Growth Hormone