Kisspeptin is a neuropeptide that regulates the hypothalamic-pituitary-gonadal axis in mammals. This study investigated the effects of kisspeptin-10 on plasma estradiol concentrations in the male Uromastyx hardwickii lizard. The study found that intraperitoneal administration of kisspeptin-10 at doses of 1, 10, and 50 μg significantly increased serum estradiol levels within 1-4 hours after injection. Administration of hCG also increased estradiol levels. Co-administration of a kisspeptin antagonist prevented the kisspeptin-induced rise in estradiol. The results suggest that kisspeptin regulates estradiol

1. Effects of Kisspeptin on plasma
Estradiol concentrations in Uromastyx
hardwickii
Hasan Shafique and Dilnaz
M. Phil. A/H Physiology Laboratory,
Quaid-i-Azam University, Islamabad.

2. Introduction
• Kisspeptins (Metastin)
– KiSS-1 mRNA expression in the basal ganglia,
hypothalamus, amygdala, subtantia nigra, hippocampus.
– Expression in the dorsomedial hypothalamic nucleus,
ventromedial nucleus and arcuate within the
hypothalamus, nucleus of the solitary tract and the
caudal ventrolateral medulla.
– Also in telencephalon, diencephalon, mesencephalon,
metencephalon and myelencephalon.

3. Introduction
• Kisspeptins (Metastin)
– Product of KiSS-1 gene.
– Kisspeptin-54, Kisspeptin-14, Kisspeptin-13, Kisspeptin-10
– Level of activity
– Binds with AXOR12/ hOT7T175/ GPR54

4. Introduction
Structure of human prepro-kisspeptin

5. Introduction
Kisspeptin-induced intracellular pathway

6. Introduction
• Kisspeptins (Metastin)
– Effects on breast cancer, papillary thyroid carcinoma,
pancreatic cancer cells, and ovarian carcinoma cells
– Regulate the levels of GnRH from the hypothalamic
GnRH neurons
– Key regulator of hypothalamic-pituitary-gonadal axis
– As a master switch for puberty

7. Introduction
• Kisspeptins (Metastin)
– Glucose-induced insulin secretion
– Expression in coronary artery and umbilical vein
– Vasoconstrictor
– As an anticoagulant of blood

8. Introduction
• Similar role in fish and amphibians has also been indicated
• The neuroendocrine and neuromodulatory roles of
kisspeptin are presently unknown in reptiles.

9. Aims and Objectives
• Acute intraperitoneal administration in investigating the
role of kisspeptin-10 in modulating serum estradiol levels in
non-breeding season in male Uromastyx harwickii.

10. Study Design
• Group-1 Normal Control
• Group-2 1 g kisspeptin
• Group-3 10 g kisspeptin
• Group-4 50 g kisspeptin
• Group-5 100 g kisspeptin
• Group-6 70 IU hCG
• Group-7 100 IU hCG
• Group-8 50 g kp Antagonist + 50 g kp
• Group-9 50 g kp + Saline

11. Materials and Methods

12. Analysis of Results
• Serum estradiol concentrations were estimated through
Enzyme Immunoassay (EIA/ELISA).
• Paired ANOVA and single factor one way ANOVA

13. Results
• Significant increase in serum estradiol levels upon
administration of all doses of kisspeptin (p<0.05).
• Increase in serum estradiol levels upon administration of
hCG treatment groups (p<0.05).
• Kisspeptin antagonist along with kisspeptin treatment
group.
• Kisspeptin antagonist treatment group.

14. Fig 3.1 Effect of kisspeptin-10 administration at the dose of 1 μg on serum
estradiol concentration in male Uromastyx hardwickii. Note significant
increase at 1 hr and 2 hrs post injection. Mean ±SEM, P< 0.001

15. Fig 3.2 Effect of kisspeptin-10 administration at the dose of 10 μg on serum
estradiol concentration in male Uromastyx hardwickii. Note significant
increase at 1 hr and 4 hrs post injection. Mean ±SEM, P< 0.001

16. Fig 3.3 Effect of kisspeptin-10 administration at the dose of 50 μg on serum
estradiol concentration in male Uromastyx hardwickii. Note significant
increase at 1 hr post injection. Mean ±SEM, P< 0.001.

17. Fig 3.4 Effect of hCG administration at the dose of 100 IU on serum
estradiol concentration in male Uromastyx hardwickii. Note significant
increase at 30 min, 1 hr, 2 hrs and 4 hrs post injection. Mean ±SEM, P<
0.001.

18. Fig 3.5 Effect of kisspeptin antagonist administration at dose of 50 μg on
serum estradiol concentration in male Uromastyx hardwickii. No significant
difference was observed from control.

19. Discussion
• Adult mice, sheep, cows, primates
• 85% homology in rat receptor80% homolgy in mice, 40 % in
non-mammalian vertebrates, such as bullfrogs.
• Kisspeptin-10 profoundly affect serum concentration of
estradiol in male Uromastyx hardwickii, which clearly proves
that kisspeptin is fully active in reptiles and has roles in
reptilian reproduction similar to those described in
mammals, but still has to be confirmed by further scientific
research.

20. Thank You