The ovine hypothalamus and pituitary have markedly different distribution of C-type natriuretic peptide forms.
C-type natriuretic peptide (CNP) was measured in the hypothalamus and pituitary of four sheep by radioimmunoassay after extraction. The mean concentration of CNP in the hypothalamus was 1.01 +/- 0.08 pmol/g and 45.8 +/- 12.8 pmol/g in the pituitary. Analysis of these extracts by size exclusion HPLC showed the presence of two immunoreactive CNP components that cochromatographed with porcine CNP-53 and CNP-22 standards. Similar amounts of CNP-53- and CNP-22-like IR-CNP were present in the ovine hypothalamus (ratio 0.9:1), whereas in the pituitary, the bulk of the immunoreactive CNP was in the CNP-53-like form. These results show major differences in the distribution of IR-CNP forms between the hypothalamus and pituitary, which may reflect differences in CNP prohormone processing in these two tissues.
Yandle
T G
TG
Department of Endocrinology, Christchurch Hospital, New Zealand.
Fisher
S
S
Charles
C
C
Espiner
E A
EA
Richards
A M
AM
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D007031:Hypothalamus / Q000737:chemistry*; D020098:Natriuretic Peptide, C-Type; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009928:Organ Specificity / Q000502:physiology; D010902:Pituitary Gland / Q000737:chemistry*; D011863:Radioimmunoassay; D012756:Sheep / Q000378:metabolism*
D009419:Nerve Tissue Proteins; D020098:Natriuretic Peptide, C-Type; D009320:Atrial Natriuretic Factor