PMID- 9324071
OWN - NLM
STAT- MEDLINE
DCOM- 19971024
LR  - 20190701
IS  - 0024-3205 (Print)
IS  - 0024-3205 (Linking)
VI  - 61
IP  - 13
DP  - 1997
TI  - Fasting-induced suppression of hypothalamic-pituitary-gonadal axis in the adult 
      rhesus monkey: evidence for involvement of excitatory amino acid 
      neurotransmitters.
PG  - 1293-300
AB  - The present study was designed to examine whether acute food-restriction in 
      non-human primates, suppresses hypothalamic-pituitary-testicular (HPT) axis via 
      alterations in the excitatory amino acid (EAA) neurotransmitter-utilizing drive 
      to the GnRH neuron. This was achieved indirectly by comparing the plasma 
      testosterone (T) responses to administration of an excitatory amino acid 
      analogue, N-methyl-D,L-aspartic acid (NMA), in acutely fasted and normal fed 
      monkeys. A set of 4 chair-restrained adult male rhesus monkeys, was assigned to 
      the following treatments: a) normal feeding, b) one-day fasting (omission of 
      morning and afternoon meals), c) normal feeding+NMA (15 mg/kg BW) and d) one-day 
      fasting+NMA (15 mg/kg BW). Starting 1 h after the provision or omission of the 
      afternoon meal, frequent blood sampling was initiated at 15-min intervals for a 
      period of 3-h. NMA was administered as an iv bolus 1 h after start of the 
      sampling. Secretion of T was affected (P<0.005) by the treatments. A peak in T 
      was evident during the first h of the sampling in fed but not fasted monkeys. 
      Mean 3-h T concentrations were suppressed (P<0.001) by the fasting. 
      Administration of NMA in fasting conditions resulted into an acute stimulation of 
      T secretion in 2 of the 4 monkeys. However, mean 60-min post-NMA T concentrations 
      were greater (P<0.05) than those prevailing during the same period in fasted 
      animals not given NMA. In contrast, all 4 fed-monkeys showed significant T 
      elevations in plasma immediately following the NMA challenge and mean T levels 
      during the 60-min post-NMA period were higher (P<0.05) than those in fed animals 
      not injected with NMA, at a comparable time. Testosterone area under the curve 
      for the 2-h post-NMA period was greater (P<0.05) in fed- than in fasted-monkeys. 
      These results indicate that although NMA can stimulate GnRH release both in fed 
      and short-term fasting conditions, the response appears to be suppressed in the 
      later situation suggesting that fasting-induced suppression of the HPT axis in 
      the adult male rhesus monkey may involve a reduction in the sensitivity of GnRH 
      neurons to the EAA neurotransmission.
FAU - Shahab, M
AU  - Shahab M
AD  - Department of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
FAU - Zaman, W
AU  - Zaman W
FAU - Bashir, K
AU  - Bashir K
FAU - Arslan, M
AU  - Arslan M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Life Sci
JT  - Life sciences
JID - 0375521
RN  - 0 (Excitatory Amino Acid Agonists)
RN  - 0 (Excitatory Amino Acids)
RN  - 0 (Neurotransmitter Agents)
RN  - 3XMK78S47O (Testosterone)
RN  - 6384-92-5 (N-Methylaspartate)
SB  - IM
MH  - Animals
MH  - Excitatory Amino Acid Agonists/pharmacology
MH  - Excitatory Amino Acids/*physiology
MH  - Fasting/*physiology
MH  - Food
MH  - Hypothalamus/*physiology
MH  - Macaca mulatta
MH  - Male
MH  - N-Methylaspartate/pharmacology
MH  - Neurotransmitter Agents/*physiology
MH  - Pituitary Gland/*physiology
MH  - Testis/*physiology
MH  - Testosterone/metabolism
EDAT- 1997/01/01 00:00
MHDA- 1997/11/04 00:01
CRDT- 1997/01/01 00:00
PHST- 1997/01/01 00:00 [pubmed]
PHST- 1997/11/04 00:01 [medline]
PHST- 1997/01/01 00:00 [entrez]
AID - S0024320597006747 [pii]
AID - 10.1016/s0024-3205(97)00674-7 [doi]
PST - ppublish
SO  - Life Sci. 1997;61(13):1293-300. doi: 10.1016/s0024-3205(97)00674-7.