Local renin-angiotensin system in the pineal gland.
Besides the classical endocrine renin-angiotensin system (RAS), a local RAS has been described also in the brain. We attempted to clarify the existence of a local RAS in the pineal gland. Through the use of a ribonuclease protection assay, it proved possible to detect the mRNA for angiotensinogen (AOGEN), for the angiotensin receptor type 1A (AT1a) and 1B (AT1b) and for the angiotensin-converting enzyme (ACE) in pineal glands from rats. Renin mRNA, however, could not be found by this method. By in situ hybridization and immunocytochemistry, AOGEN mRNA was co-localized with the astrocyte marker glial fibrillary acidic protein. AT1b mRNA expression exceeded the expression of AT1a mRNA and was co-localized with the pinealocyte-specific tryptophan hydroxylase. Thus, in the mammalian pineal gland there is a local formation of the components of the RAS. The presence of angiotensin II receptors further substantiates a role for angiotensins and the pineal RAS in the physiology of this gland.
Baltatu
O
O
Hypertension Research, Max-Delbrück-Center for Molecular Medicine (MDC), D-13122 Berlin-Buch, Germany.
Lippoldt
A
A
Hansson
A
A
Ganten
D
D
Bader
M
M
D000808:Angiotensinogen / Q000235:genetics*; D000818:Animals; D005815:Genetic Code; D017403:In Situ Hybridization; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D010870:Pineal Gland / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011945:Receptors, Angiotensin / Q000235:genetics*; D012084:Renin-Angiotensin System / Q000502:physiology*; D012260:Ribonucleases
D012333:RNA, Messenger; D011945:Receptors, Angiotensin; D000808:Angiotensinogen; D012260:Ribonucleases; D007703:Peptidyl-Dipeptidase A