Expressions of per1 clock gene and genes of signaling peptides vasopressin, vasoactive intestinal peptide, and oxytocin in the suprachiasmatic and paraventricular nuclei of hypertensive TGR[mREN2]27 rats.
Hypertensive rats with multiple extra copies of the renin gene (TGR) exert an inverted circadian blood pressure (BP) profile. We investigated whether circadian oscillations in the hypothalamic suprachiasmatic nucleus (SCN), a main circadian oscillator, and the paraventricular nucleus (PVN), involved in BP control, are influenced in TGR rats. The expression of the clock gene per1, a marker of circadian timing, was measured in the SCN and PVN. Moreover, the expression of genes encoding vasopressin (AVP), vasoactive intestinal peptide (VIP) in the SCN, and AVP and oxytocin (OXT) in the PVN were studied by in situ hybridization. Expression of the per1 gene showed a distinct circadian rhythm in both the SCN and PVN with no differences observed between the TGR and control Sprague–Dawley (SD) rats. The expression of avp in the SCN was rhythmic in both strains and moderately higher in TGR than in SD rats while no significant changes were found in the PVN. The expression of vip in the SCN and oxt in the PVN did not differ between both strains. Our results may indicate that changes occurring downstream to the SCN are responsible for the development of the inverted BP rhythm in TGR hypertensive rats.
Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University Bratislava, Slovak Republic.
Zuzana
Z
Dzirbíková
Alexander
A
Kiss
Monika
M
Okuliarová
Libor
L
Kopkan
Ludĕk
L
Cervenka
D000818:Animals; D001127:Arginine Vasopressin / Q000235:genetics* / Q000378:metabolism; D001345:Autoradiography; D001794:Blood Pressure / Q000502:physiology; D002940:Circadian Rhythm / Q000235:genetics; D005786:Gene Expression Regulation; D006339:Heart Rate / Q000502:physiology; D006973:Hypertension / Q000235:genetics / Q000503:physiopathology; D009043:Motor Activity / Q000502:physiology; D010121:Oxytocin / Q000235:genetics* / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism*; D056950:Period Circadian Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000235:genetics; D013493:Suprachiasmatic Nucleus / Q000378:metabolism* / Q000503:physiopathology; D014660:Vasoactive Intestinal Peptide / Q000235:genetics* / Q000378:metabolism
C539024:Per1 protein, rat; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D001127:Arginine Vasopressin; D014660:Vasoactive Intestinal Peptide; D010121:Oxytocin