Lamprey Hormones

Cross references:   Lamprey Neuropeptides     Lamprey Neuromodulators  
Lamprey Cortisol, etc.    Amphioxus Hormones    Shark Hormones    
Teleost Hormones  
Salamander Hormones   

1954    983<984
    The occurrence of a waterbalance-, a melanophore-expanding and an oxytocic principle in the pituitary gland of the river-lamprey (Lampetra fluviati...
No PubMed Abstract.
    282 Related citations:

Google Abstract

Steroid formation in the larval and parasitic adult sea lamprey (Goog) 
Only abstract available online. 
    "Presumptive adrenocortical tissue (PAT) ... from both parasitic adults and larvae formed 11-deoxycortisol (S), 17α-hydroxyprogesterone (17αOHP), and androstene dione (AD) but no cortisol (F) cortisone (E), corticosterone (B), 11-deoxycorticosterone (DOC), or testosterone (T) were formed. ... Testicular tissue failed to produce F, E, B, S, T, 17αOHP, or AD. However, testicular tissue did form DOC ...

Immunocytochemical studies of luteinizing hormone-releasing hormone in brains of agnathan fishes: I. Comparisons of adult Pacific lamprey (Entosphenus tridentata) and the Pacific hagfish (Eptatretus stouti)
    No PubMed Abstract, but there was a: 
    Google Abstract:
    "An immunocytochemical unlabeled antibody enzyme technique has been applied to localize mammalian-like immunoreactive luteinizing hormone-releasing hormone (ir-LH-RH) in central nervous tissue of Pacific lamprey (Entosphenus tridentata; anadromous spawning migrants) and of Pacific hagfish (Eptatretus stouti, sexually undifferentiated and mature). Specific immunocytochemical staining was located over perikarya in the preoptic nucleus of lampreys; beaded axons containing herring body-like dilatations were stained and appeared to pass ventro-posteriorly into the infundibulum where presumed nerve endings were observed in the neurohypophysis. Cell bodies exhibiting ir-LH-RH were distinct from those, presumably vasotocinergic ones, which stained with aldehyde fuchsin. Specific staining was absent in other regions of the lamprey brain, in control preparations, and in any part of the hagfish central nervous tissues. The possible hypophysiotropic actions of ir-LH-RH in the lamprey preoptico-neurohypophysial system are unclear because no anatomical relationship is evident which might provide for transfer of hypothalamic influences to the pars distalis. However, detection of mammalian-like ir-LH-RH in brain of this primitive agnathan fish indicates that this peptide may be of great evolutionary antiquity."  
    and 109 Related PubMed citations:   

Immunocytochemical studies of luteinizing hormone-releasing hormone in brains of agnathan fishes: II. Patterns of immunoreactivity in larval and maturing Western brook lamprey (Lampetra richardsoni)
    No PubMed Abstract, but there was a
Google Abstract:
    "An immunocytochemical unlabeled antibody enzyme technique has been applied to localize mammalian-like immunoreactive luteinizing hormone-releasing hormone (ir-LH-RH) in central nervous tissues of Western brook lamprey (Lampetra richardsoni). In larval animals faint specific immunocytochemical staining was found over perikarya in the posterior preoptic nucleus (PON), in fiber tracts passing ventro-posteriorly into the infundibulum, and in nerve endings in the neurohypophysis (NH). In brains of nonreproductive adults, faint staining of cell bodies was observed throughout the PON; staining of NH was intense. In reproductive adults, heavy staining was noted in PON perikarya, in beaded axons containing Herring body-like dilatations, and in NH. Perikarya with ir-LH-RH were distinct from those, presumably vasotocinergic ones, which stained with aldehyde fuchsin; specific immunocytochemical staining was absent in other brain regions and in control preparations. A change in number of cells stained, and in quality of staining was coincident with metamorphosis and sexual maturation; mechanisms by which ir-LH-RH might be transported from the preoptico-neurohypophysial system to the pars distalis to exert any physiological actions have not been established."
    as well as 104 Related citations:
    and 4 Cited by's.

Estrogen target cells in the forebrain of river lamprey, Ichthyomyzon unicuspis
    "Estrogen-concentrating cells in the brain of river lamprey, Ichthyomyzon unicuspis, are identified and mapped by thaw-mount autoradiography. After injection of 3H-estradiol-17 beta, cells with nuclear concentration of radioactivity are found in the ventral periventricular area of the telencephalon, and in preoptic, central hypothalamic, and thalamic regions of the diencephalon, while in the pallium no such target cells are found. Injection of unlabeled estradiol prior to the administration of 3H-estradiol reduces of eliminates the nuclear concentration of radioactivity. The autoradiographic results demonstrate the presence of estrogen target cells in the brain of descendents of one of the phylogenetically earliest vertebrate lines. The topographical distribution of these target neurons, which are accumulated in certain periventricular structures, is similar to the distribution of estrogen target neurons described previously for other nonmammalian and mammalian vertebrates. Accordingly, estrogen feedback and activation sites are present throughout vertebrate phylogeny."
    174 Related citations:
    and 2 Cited by's.  

Autoradiographic studies of estrogen target cells in the forebrain of larval lamprey, Petromyzon marinus
    "The distribution of estrogen target neurons is assessed in the forebrain of larval sea lamprey, Petromyzon marinus, by the use of thaw-mount autoradiography. Following the injection of [3H]estradiol-17 beta, radioactively labeled neurons are found in the ventral telencephalon and in the ventral and dorsal diencephalon, including preoptic, central hypothalamic, and thalamic regions. In the pallium no labeled cells exist. Pituitary glands, obtained from two of the animals, contain no labeled cells. The topographical distribution of estrogen target neurons in larval lamprey is similar to that of adult animals. The number of target neurons in larval lamprey, however, is lower than in the adult. The presence of target cells indicates that gonadal steroids act on the brain at this early stage of development. The lack of concentration of estrogen in pituitary cells suggests an absence of feedback regulation of estrogen at the pituitary level."
    174 Related citations:   
    and 1 Cited by.


Endocrine events associated with spawning behavior in the sea lamprey (Petromyzon marinus). 

Only abstract available online.  I  got the PDF from the library.   
from the Abstract:   
Levels of estradiol, progesterone, and testosterone were determined in plasma of sea lamprey (Petromyzon marinus) undergoing certain behaviors associated with spawning in natural and artificial stream environments.    
    Significantly higher levels of estradiol, progesterone, and testosterone were found in males than in females. In the artificial spawning channel, levels of estradiol were significantly higher in females exhibiting resting and swimming behaviors than in fanning, nest building, and spawning behaviors. No significant correlation was found with either progesterone or testosterone levels and the various reproductive behaviors.  
    The data presented are the first experimental evidence that suggest gonadal steroids may be correlated with certain reproductive behaviors in the sea lamprey."      

Effects of lamprey gonadotropin-releasing hormone-III on steroidogenesis and spermiation in male sea lampreys.    
from the Abstract:   
The biological activities of lamprey gonadotropin-releasing hormone-III (GnRH-III) were determined in the adult male sea lamprey, Petromyzon marinus. One injection of lamprey GnRH-III at 0.1 or 0.2 microgram/g body wt stimulated plasma estradiol and progesterone levels in adult male sea lampreys undergoing final maturation. Four successive injections of lamprey GnRH-III at 0.1 microgram/g of lamprey GnRH-1 at 0.2 microgram/g induced spermiation in 78 or 30% of the lampreys, respectively, compared to 0% in controls by Day 16. In summary, lamprey GnRH-III is biologically active in stimulating the pituitary-gonadal axis in adult male lampreys."  

Characteristics of GnRH binding in the gonads and effects of lamprey GnRH-I and -III on reproduction in the adult sea lamprey.  
from the Abstract:   
In the present study, both lamprey GnRH-I and -III stimulated steroidogenesis and induced ovulation in adult female sea lampreys during their final reproductive stage. ... Lamprey GnRH-III also had a direct stimulatory effect on estradiol production in the sea lamprey gonads in vitro. ... ... In summary, lamprey GnRH-III is biologically active in stimulating the pituitary-gonadal axis in adult female sea lampreys. This is the first report demonstrating the presence of a GnRH binding site in the gonads of an Agnathan. The evidence for a direct stimulatory effect of lamprey GnRH in the gonads, the presence of GnRH binding site, and the absence of GnRH in the plasma suggest that, like other vertebrates including rat, rabbit, teleost fish, and human, there may be a GnRH-like factor produced in the gonads of the lamprey and it may act as a paracrine/autocrine modulator of gonadal function. This study further strengthens the paracrine regulatory role of GnRH peptides in the gonads of vertebrates, which appear to be evolutionarily conserved."  

Estrogen Is the Most Ancient of (Steroid) Hormones (Goog) 
Full length article in plain English available online. 
By reconstructing a DNA sequence that existed more than 450 million years ago, Joe Thornton, a research scientist and evolutionary biologist at Columbia's Earth Institute, has revealed how new hormones emerged during evolution, concluding that the female hormone estrogen is the most ancient of all steroid hormones but that its role in differentiating the sexes from each other developed much later."  

The dawn and evolution of hormones in the adenohypophysis.  
Abstract only.   Discusses evolution of
adrenocorticotropin (ACTH), melanotropin (MSH), beta-endorphins (beta-END), growth hormone (GH)
, insulin-like growth factor (IGF), gonadotropin (GTH), thyrotropin (TSH), PRL, LH and FSH
In gnathostomes, adrenocorticotropin (ACTH) and melanotropin (MSH) together with beta-endorphins (beta-END) are encoded in a single gene, designated as proopiomelanocortin (POMC), however in sea lamprey, ACTH and MSH are encoded in two distinct genes, proopoicortin (POC) gene and proopiomelanotropin (POM) gene, respectively. The POC and POM genes are expressed specifically in the rostral pars distalis (RPD) and the pars intermedia (PI), respectively. Consequently, the final products from both tissues are the same in all vertebrates, i.e., ACTH from the PD and MSH from the PI."  
Sea lamprey growth hormone (GH) appears to be the only member of the GH family in the sea lamprey, which suggests that GH is the ancestral hormone of the GH family that originated first in the molecular evolution of the GH family in vertebrates and later, probably during the early evolution of gnathostomes."  
lampreys have a single gonadotropin (GTH) gene, which duplicated after the agnathans and prior to the evolution of gnathostomes to give rise to LH and FSH."  

The origins of the vertebrate hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-thyroid (HPT) endocrine systems: new insights from lampreys.  
Abstract only. 
    " Lampreys as basal vertebrates are the earliest evolved vertebrates for which there are demonstrated functional roles for two gonadotropin-releasing hormones (GnRHs) that act via the hypothalamic-pituitary-gonadal axis controlling reproductive processes."  
The existing data suggest the existence of a primitive, overlapping yet functional HPG and HPT endocrine systems in this organism, involving one possibly two pituitary glycoprotein hormones and two glycoprotein hormone receptors as opposed to three or four glycoprotein hormones interacting specifically with three receptors in gnathostomes."  

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