Beta-adrenergic receptor in the anterior lobe of rat pituitary: Immunohistochemical study with reference to ACTH

S120 POSTNATAL ENTRAINING MECHANISM OF RAT PUP CIRCADIAN RHYTHM. M.Sugishita. K.Ohi. F.Kato. M.Taka~hima. Y.Takeuchi and K.Takahashi, Div. 0I Mental Disorder Research. National Institute of N e u r o s c i e n c e , NCNP. 4-i-i Ogawahigashi, Kodaira. Tokyo 187.Japan To investigate the maternal entraining m e c h a n i s m of the circadian r h y t h m in rat pups, we compared the entraining p o t e n c y of several m a n i p u l a t i o n s k n o w n to entrain pups' rhythm: periodic mother deprivation (PMD), food restriction in mother, crossfostering and melatonin administration. All p u p s e x a m i n e d were optically e n u c l e a t e d on the day of birth. The circadian rhythm was measured by pineal N-aeetyltransferase (NAT) activity. Free access to m o t h e r was restricted to either light (L-suckling> or dark phase t h r o u g h o u t the experiment. On the 10th p o s t n a t a l day, 24h patterns of NAT activity exhibited a marked day-night difference and the rhythm of Dsuckling group was 180 degrees out of both phases in L-suckling and n o n - P M D control groups. On the other hand, pups' r h y t h m at the same age was not affected w h e n the pups were raised either by a foster m o t h e r with r h y t h m r e v e r s e d to that of natural mother or by a mother subjected to restriction of feeding. T h e s e results indicate that PMD is the most potent entrainer. To observe the effect of melatonin, pups were injected with melatonin (100~g/pup) at 0800 or 2000h e v e r y day. On the d a y of parturition, both pineal b o d y and eyes in m o t h e r were r e m o v e d . A d m i n i s t r a t i o n at 08OOh shifted the NAT rhythm,. However, PMD using pinealectomized and blinded mothers still reversed the rhythm of D-suckling group, s u g g e s t i n g that m e l a t o n i n d o e s not play an essential role in postnatal entraining, although it may be partly involved in the mechanism.

BETA-ADRENERGIC RECEPTOR IN THE ANTERIOR LOBE OF IMMUNOHISTOCHEMICAL STUDY WITH REFERENCE TO ACTH MAKOTO SATO*, YOSHIYUKI KUBOTA*, MASAYA TOHYAMA, D e p a r t m e n t o f

Anatomy

University

530.

Cells in

Medical bearing

the a n t e r i o r

receptor of New

4-Nakanoshima,

D-adrenergic lobe of

receptors

Kita-ku,

Osaka

Japan,

were demonstrated

the rat p i t u i t a r y

using

PITUITARY:

receptor. i.p.),

Beta-adrenergic

Male

Wistar

rats

were

perfused

transcardially,

receptor

cells

were

anesthetized

II,

Os__aJta

immunohistochemically

antiserum

against

B2-adrenergic

of the g u i n e a p i g lung ( g e n e r o u s g i f t f r o m P r o f e s s o r M a l b o n , York, U . S . A . ) . T h i s a n t i s e r u m was c o n f i r m e d to cross-react

adrenergic (60mg/kg,

School,

RAT

S t a t e Univ. with ~1-

with

sodium

for

immunohistochemistry.

and p r o c e s s e d

sparsely distributed

pentobarbital

in the a n t e r i o r

lobe

of

the p i t u i t a r y . T h e i r fine s t r u c t u r e s w e r e s i m i l a r to those of adrenocorticotropic h o r m o n e (ACTH) s e c r e t i n g cells. S u b s e q u e n t a n a l y s i s of s e r i a l s e c t i o n s s h o w e d that cells containing # - a d r e n e r g i c r e c e p t o r a l s o h a v e ACTH. M o r e than 7OX of ACTH cells

contain

of a d r e n e r g i c

D-adrenergic systems

receptor.

in A C T H

Thus,

our

findings

suggest

the

involvement

secretion.

IMMUNOHISTOCHEMICAL STUDIES ON TYROSINE HYDROXYLASE(TH)-POSITIVE, DOPAMINE -HYDROXYLASE(DBH)-NEGATIVE NEURON-LIKE CELLS IN THE PINEAL GLAND OF GOLDEN HAMSTERS. Y B H E S H I O T A N I I , KUI LONG J I N * I , 2 , YURIKO KAWAI t AND HIROSHI KIYAMA1, i D e p a r t m e n t of N e u r o a n a t o m y , B i o m e d i c a l R e s e a r c h C e n t e r , O s a k a University Medical School, Osaka 530, Japan and 2 D e p a r t m e n t of A n a t o m y . Y a n b i a n M e d i c a l C o l l e g e . Yanbian, China. D o u b l e i m m u n o s t a i n i n g for t y r o s i n e h y d r o x y l a s e ( T H ) and dopamine # -hydroxylase (DBH) in the pineal gland revealed many TH-positive, DBH-negative, neuron-like c e l l s in g o l d e n h a m s t e r s , but not in r a t s and g e r b i l s . T h e y w e r e s c a t t e r e d in the meshwork of THand D B H - p o s i t i v e f i b e r s t h r o u g h o u t the p a r e n c h y m a . T h e i r cell b o d i e s w e r e oval or s p i n d l e - s h a p e d ( m a x i m u m d i a m e t e r : 1 5 - 2 0 a m) and contained a large round nucleus in the center. T h e y s o m e t i m e s had one or two s h o r t cell processes. E l e c t r o n - m i c r o s c o p i c a l l y , a n u m b e r of m i t o c h o n d r i a , r i b o s o m e s or Golgi apparatus w e r e c o n t a i n e d in the c y t o p l a s m . T h e p l a s m a m e m b r a n e was in c l o s e contact w i t h p i n e a l o c y t e s , t h e i r p r o c e s s e s , and T H - p o s i t i v e or T H - n e g a t i v e n e r v e term i n a l s , a l t h o u g h m e m b r a n e s p e c i a l i z a t i o n was not c o n s p i c u o u s . Bilateral superior c e r v i c a l g a n g l i o n e c t o m y s t r i k i n g l y d i m i n i s h e d the n u m b e r of THand DBH-positive nerve fibers, but did not a f f e c t the n u m b e r of T H - p o s i t i v e cells. Ontogenetic s t u d y r e v e a l e d that t h e s e c e l l s f i r s t a p p e a r e d on the 6th p o s t n a t a l d a y and therea f t e r i n c r e a s e d in n u m b e r .