Cons of a bioassay

1. Cons of a bioassay- foremost the response to a endocrine by a specific tissue may non reflect the ‘in vivo ‘ response Your Project Will Be Complete Rapidly! – anchor . For illustration, a endocrine may be modified by another factor within the tissue before it acts on the tissue. Furthermore, the endocrine that you are proving i.e the figure of contractions in uterine tissue in response to a specific Pitocin concentration, may non be wholly be due to oxytocin i.e. PGF2a is besides psent in uterine tissue which acts locally to do contractions besides ( Callegari et al, 2005 ) . Besides, an animate being may necessitate to be killed in order to insulate one organ merely i.e. the womb in mice. There is besides biological fluctuation between species i.e. human and mouse, and so the physical result in response to a peculiar endocrine in mice may non reflect what the result is in adult male.

Professionals of a bioassay-allows you to find whether a endocrine is psent in a peculiar tissue and/or plasma. This gives you an thought of how the endocrine may move ‘in vivo ‘ and how the effects may be modified in a dose response manner on a peculiar tissue. The results on endocrine responses observed in mice tissue might repsent the manner the drug works in adult male ( Bulletti, 2005 ) . An unknown concentration of a peculiar endocrine can be devised. You can besides utilize a bio-assay to configure the biological response of an exogenic substance, and to do comparings of the assortment of effects of different substances on different tissues.

2. Harmonizing to Furchgott and Zawadzki ( 1980 ) the type of cut of tissue does non count. Equally long as the subdivision is carried out carefully so that the endothelial cells remain integral. The myometrium is portion of an endothelial bed that contains the receptors for Pitocin. Basically the cut does non count ; nevertheless, the receptors need to stay integral.

3. We would automatically believe that in the ‘absence of any endocrines ‘ the baseline activity will be zero. However, this is non the instance i.e. if the cotton twine was interfered with the baseline activity may be altered. Furthermore, the baseline activity likely is non a contemplation of the ‘absence of endocrines ‘ . Therefore, it is really of import to obtain a baseline bio-assay measuring, to set up how psence of other factors in the tissue could interfere with subsequent measurings.

4. The greater the sum of Pitocin added to the H2O bath the greater was the frequence. However, the amplitude sid non alteration. In other words a greater sum of Pitocin added to the H2O bath-the greater figure of contractions within the womb, although the force of the strength of the contractions was non altered.

5. To quantitate the sum of Pitocin of the unknown ( the sum of Pitocin in IU per g in mice pituitary tissue ) the country under the curves for each concentration ( 1IU, 5IU, and 10IU ) added to the H2O bath-the terra incognita was calculated. The country ( uterine work ) was figured by publishing the curves on graph paper, cutting out the curves and weighing the paper in gms and spliting the weight by the weight of a 1cm2 piece of paper to give the uterine work ( country under curve ( cm2 ) ) . Subsequently, the value of the uterine work for each concentration including the unknown concentration plotted on the graph. Please see graph and computation on the following page. Calculating the country in this manner was a more simple option compared to ciphering the work by utilizing the amplitudes ( which did non vary well ) and the frequence, or by numbering the figure of squares underneath the curves.

6. Please see graph and computation on following page.

7/8. This check was non specific. In respects to the womb in mice other endocrines which affect the frequence of contractions are psent. For illustration, PGF2a which besides acts on the myometrium of the uterus works to increases the sum of contractions. Furthermore, Lipo-Lutin is responsible for doing uterine musculus more contractile, while estrogen and relaxin causes it to loosen up ( Blanks and Shymgol, 2007 ) .

In a pituitary, endocrines such as progestogens, estrogen ‘s, androgens, which alter uterine contractility, may be found. Additionally, vasopssin is secreted by the posterior hypophysis and binds to a receptor really similar to the Pitocin receptor within the womb ( Furchgott and Zawadzki, 1980 ) . At any one clip vasopssin may adhere to an oxytocin receptor exciting the same response ( Furchgott and Zawadzki, 1980 ) .

Therefore, depending on conditions or non and how much of the above endocrines were psent in the mice womb and the pituitary- alters the consequence of oxytocin moving entirely.

Besides, other endocrines such as lactogenic hormone, Dopastat, inhibin, LH and FSH are found within the pituitary secretory organ.

9. This bio-assay was non good in footings of its specificity as mentioned in inquiries 7/8. However, it could be made more specific i.e. add adversaries of the endocrines psent in both the uterine and pituitary tissues to the H2O bath except for Pitocin, or to insulate the Pitocin from the pituitary tissue foremost which is obtained by denseness gradient centrifugation of stray pituitary tissue, later adding it to the H2O bath.


Spaces, A. , Shmygol, S. ( 2007 ) . Myometrial map in pmaturity. Best Practice & A ; Research Clinical Obstetrics & A ; Gynaecology 21: 807-819.

Bulletti, C. , Zieglar, D. ( 2005 ) . Uterine contractility and embryo nidation. Experimental Physiology 3: 265-76.

Callegari, A.E. , Furguson-Gotschall, S. , Gibori, G. ( 2005 ) . PGF2alpha induced differential expssion of cistrons involved in turnover of extracellular matrix in rat decidual cells. Generative Biology and Endocrinolgy 3:3.

Furchgott R.F, and Zawadzki J.V. ( 1980 ) The obligatory function of endothelial cells in the relaxation of arterial smooth musculus by acetylcholine. Nature. Vol 288.