Characterization of functional melanotropin receptors in lacrimal glands of the rat.

Entwistle ML, Hann LE, Sullivan DA, Tatro JB

Peptides1 May 1990Cited by 16 (Europe PMC)

PMID2166277DOI10.1016/0196-9781(90)90046-8PepBankPUB-02166277

Publisher page PubMedAsk about this study

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study5

4 results from studies that gave the peptide. No result from this study comes from people.

01LabEx vivo tissueActivity measurement
In rat lacrimal gland sections, intense specific [125I]-NDP-MSH binding occurred throughout the acinar tissue but not in ducts or stroma.
In plain wordsIn lab tests on rat tear gland tissue, NDP-MSH bound strongly in the secreting cells but not in ducts or supporting tissue.
Peptide
Melanotan I (afamelanotide)
Outcome
Not applicableDistribution of NDP-MSH binding in lacrimal gland
Study
ratn: not reported in source
rat lacrimal gland tissue sections
Outcome group
Receptor activity and mechanism · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
Tissue distribution of MSH binding sites was determined by autoradiography following in situ binding of a radiolabeled, biologically active preparation of a superpotent alpha-MSH analog, [125I]-[Nle4,D-Phe7]-alpha-MSH ([125I]-NDP-MSH).
2 context sentences(design, population, supporting numbers)
Summary · context
Intense, specific (i.e., alpha-MSH-displaceable) [125I]-NDP-MSH binding was observed throughout lacrimal acinar tissue, but not in ducts or stroma.
Summary · context
The specific melanotropin (MSH) binding sites of rat lacrimal glands were characterized with respect to anatomic distribution, peptide specificity and selectivity, and coupling to a biological response.
Report a problemFND-0216627701
02LabIn vitro (cells)Activity measurement
In freshly isolated rat lacrimal acinar cells, specific [125I]-NDP-MSH binding was maximal within 30 minutes and rapidly reversible, with a dissociation half-time of about 15 minutes.
In plain wordsIn rat tear gland cells in the lab, NDP-MSH binding peaked within 30 minutes and reversed quickly.
Peptide
Melanotan I (afamelanotide)
Outcome
Not applicableBinding kinetics in isolated acinar cells
Study
ratn: not reported in source
freshly isolated rat lacrimal acinar cells
Outcome group
Receptor activity and mechanism · Endocrine and hormones
Studied dose
Dose not stated
Measurements
Time to maximal binding
≤ 30 min
isolated acinar cells
Dissociation half-time
≈ 15 min
isolated acinar cells
Source sentences
Summary
In freshly isolated lacrimal acinar cells, specific binding of [125I]-NDP-MSH was maximal within 30 min and rapidly reversible, with a dissociation half-time of about 15 min.
1 context sentence(design, population, supporting numbers)
Summary · context
The specific melanotropin (MSH) binding sites of rat lacrimal glands were characterized with respect to anatomic distribution, peptide specificity and selectivity, and coupling to a biological response.
Report a problemFND-0216627702
03LabIn vitro (cells)Activity measurement
In rat lacrimal acinar cells, NDP-MSH was the most potent melanotropin at inhibiting [125I]-NDP-MSH binding, with an IC50 of 1.3 x 10(-9) M.
In plain wordsIn rat tear gland cells in the lab, NDP-MSH was the strongest of the melanotropins tested at binding the receptor.
Peptide
Melanotan I (afamelanotide)
Outcome
Not applicablePotency in inhibiting tracer binding (IC50)
Study
ratn: not reported in source
freshly isolated rat lacrimal acinar cells
Outcome group
Receptor activity and mechanism · Endocrine and hormones
Studied dose
Dose not stated
Measurements
IC50
1.3 x 10(-9) M
isolated acinar cells
Source sentences
Summary
NDP-MSH was the most potent (IC50 = 1.3 x 10(-9) M).
1 context sentence(design, population, supporting numbers)
Summary · context
The specific melanotropin (MSH) binding sites of rat lacrimal glands were characterized with respect to anatomic distribution, peptide specificity and selectivity, and coupling to a biological response.
Report a problemFND-0216627703
04LabIn vitro (cells)Activity measurement
In isolated rat lacrimal acinar cells, NDP-MSH and alpha-MSH stimulated intracellular cyclic AMP accumulation.
In plain wordsIn rat tear gland cells in the lab, NDP-MSH raised cyclic AMP levels inside the cells.
Peptide
Melanotan I (afamelanotide)
Outcome
IncreaseIntracellular cAMP accumulation
Study
ratn: not reported in source
isolated rat lacrimal acinar cells
Outcome group
Receptor activity and mechanism · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
In isolated lacrimal acinar cells, alpha-MSH and NDP-MSH stimulated intracellular cyclic AMP accumulation.
1 context sentence(design, population, supporting numbers)
Summary · context
The specific melanotropin (MSH) binding sites of rat lacrimal glands were characterized with respect to anatomic distribution, peptide specificity and selectivity, and coupling to a biological response.
Report a problemFND-0216627705

Studies that did not test the peptide alone1

In this study, Melanotan I (afamelanotide) was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Melanotan I (afamelanotide).

05LabNot a test of Melanotan I (afamelanotide) aloneIn vitro (cells)Activity measurement
In rat lacrimal acinar cells, ACTH(4-10), VIP, substance P, somatostatin and ACTH(18-39) had no effect on [125I]-NDP-MSH binding.
In plain wordsIn rat tear gland cells in the lab, five other peptides did not change the binding of labelled NDP-MSH.
Peptide
Melanotan I (afamelanotide)
Outcome
No significant changeEffect of ACTH(4-10), VIP, substance P, somatostatin and CLIP on tracer binding
Study
ratn: not reported in source
freshly isolated rat lacrimal acinar cells
Outcome group
Receptor activity and mechanism · Endocrine and hormones
Source sentences
Summary
In contrast, other peptides, including ACTH(4-10) and the nonmelanotropic peptides VIP, substance P, somatostatin, and ACTH(18-39) (CLIP), had no effects on tracer binding.
1 context sentence(design, population, supporting numbers)
Summary · context
The specific melanotropin (MSH) binding sites of rat lacrimal glands were characterized with respect to anatomic distribution, peptide specificity and selectivity, and coupling to a biological response.
In this study, Melanotan I (afamelanotide) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Melanotan I (afamelanotide).
Report a problemFND-0216627704

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
13 Oct 2026, 21:44 UTC
Study results updated
Version 1
13 Oct 2026, 16:31 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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