Properties of Equine Luteinizing Hormone Alpha Subunit Alone and in ...

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and HAROLD. PAPKOFF2. Hormone .... Ryan,. 1983;. Sairam,. 1983). Equine. LH. (eLH), however, is an exception to the rule. It has been ... 10 M urea as previously described. (Papkoff,. 1974). The. oLH subunits were prepared by the.
BIOLOGY

OF

REPRODUCTION

35,

Properties

493-500

(1986)

of Equine

Luteinizing

and in Combination JANET

F. ROSER,3

Hormone

with

FRANK

Alpha

Various

Alone

Beta Subunits’

CARRICK,4

N.

Subunit

and

HAROLD

PAPKOFF2

Hormone Research Laboratory University of California San

Francisco,

California

94143

ABSTRACT Previous

studies

have

monophosphate from

immature

rats.

subunit.

To

bination

with

In

shown

(cAMP)

It was

explore

this

ovine

a radioreceptor

that

induced

equine

by

also

shown

that

phenomenon

(o)

LI-I

assay

beta,

luteinizing

hormone

follicle-stimulating the

inhibitory

further, ovine

employing

the

FSH

inhibits

(FSH)

in preparations

effect

intrinsic

beta,

‘251-oFSH

(eLH)

hormone

and and

a function

FSH-like

equine testis

was

FSH

production of the

activities beta

were

membranes

from

of cyclic

of

adenosine

of seminiferous equine

eLH

alpha

evaluated

calves,

(eLH)

alone

in several

day-old

tubules

LH

and assay

eLH

alpha in comsystems.

was

twice

as

active as oFSH, eLH alpha was 6% as active as oFSH, and other subunits Whereas oLH was only 0.1% as active as oFSH, the hybrid eLH alpha-oLI-I activity of eLH alpba-FSH beta hybrids tended to be higher than the

showed a lack of activity (